# US 2013/0158261 A1 · Protease inhibitors

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- Number: US 2013/0158261 A1
- Document ID: US20130158261A1
- Status: Published application
- Kind: A1
- Application number: 13/768,779
- Filed: 2013-02-15
- Published: 2013-06-20
- Earliest claimed: 2006-09-21
- Assignees: TaiMed Biologics, Inc.
- Inventors: Brent Richard STRANIX; Jean-Francois LAVALLEE; Nicolas LEBERRE; Valerie PERRON; Dominik HERBART; Guy MILOT; Chandra PANCHAL
- Web page: https://patentgrep.com/patent/US20130158261A1

## CPC

- C07C 311/41: to an acyclic carbon atom of a hydrocarbon radical substituted by nitrogen atoms, not being part of nitro or nitroso groups
- A61P 31/08: for leprosy
- A61P 31/18: for HIV
- A61P 43/00: Drugs for specific purposes, not provided for in groups A61P1/00-A61P41/00
- C07C 271/22: to carbon atoms of hydrocarbon radicals substituted by carboxyl groups
- C07C 311/42: to an acyclic carbon atom of a hydrocarbon radical substituted by carboxyl groups
- C07D 213/56: Amides
- C07D 213/82: in position 3
- C07D 265/36: condensed with one six-membered ring
- C07D 307/79: with only hydrogen atoms, hydrocarbon or substituted hydrocarbon radicals, directly attached to carbon atoms of the hetero ring
- C07D 317/62: with hetero atoms or with carbon atoms having three bonds to hetero atoms with at the most one bond to halogen, e.g. ester or nitrile radicals, directly attached to atoms of the carbocyclic ring
- C07D 319/18: Ethylenedioxybenzenes, not substituted on the hetero ring
- C07D 405/12: linked by a chain containing hetero atoms as chain links
- C07D 413/12: linked by a chain containing hetero atoms as chain links
- C07F 9/06: without P—C bonds
- C07F 9/091: {with hydroxyalkyl compounds with further substituents on alkyl}
- C07F 9/58: Pyridine rings
- C07C 2601/14: The ring being saturated
- C07C: ACYCLIC OR CARBOCYCLIC COMPOUNDS
- A61P: SPECIFIC THERAPEUTIC ACTIVITY OF CHEMICAL COMPOUNDS OR MEDICINAL PREPARATIONS
- C07D: HETEROCYCLIC COMPOUNDS (macromolecular compounds C08)
- C07F: ACYCLIC, CARBOCYCLIC OR HETEROCYCLIC COMPOUNDS CONTAINING ELEMENTS OTHER THAN CARBON, HYDROGEN, HALOGEN, OXYGEN, NITROGEN, SULFUR, SELENIUM OR TELLURIUM (metal-containing porphyrins C07D487/22)

## Abstract

The present invention provides HIV protease inhibitors of formulas I, IA, IB, Ib or II, or pharmaceutically acceptable salts thereof, wherein R2 may be, for example, 2-pyridyl-CH2—, 3-pyridyl-CH2—, 4-pyridyl-CH2—, a sulfonyl group as described in the formulas herein including benzenesulfonyl or thiophenesulfonyl groups, R2a—CO)—, R2a being selected from the group consisting of piperonyl, 2-pyranzinyl (unsubstituted or substituted with H, or an alkyl of 1 to 4 carbon atoms) or a picolylamine group as described herein, wherein R3 may be, for example, a phenyl group or diphenylmethyl group as described herein, and wherein Cx may be, for example, COOH, CONR5R6, CH2OH or CH2OR7.

## Claims

### Claim 1

A compound of formula I
or a pharmaceutically acceptable salt thereof or a stereoisomer thereof,
wherein Cx is selected from the group consisting of CH2OH, COOM′, CONR5R6, and CH2OR7, wherein R7 is selected from the group consisting of (HO)2P(O) and (MO)2P(O), wherein M′ is H or an alkali metal or alkaline earth metal, wherein M is an alkali metal or alkaline earth metal and a group of formula R7A—CO—, R7A being selected from the group consisting of a straight or branched alkyl group of 1 to 6 carbon atoms, a cycloalkyl group having 3 to 6 carbon atoms, a cycloalkylalkyl group having 3 to 6 carbon atoms in the cycloalkyl part thereof and 1 to 3 carbon atoms in the alkyl part thereof, an alkyloxy group of 1 to 6 carbon atom, —CH2OH, CH3O2C—, CH3O2CCH2—, Acetyl-OCH2CH2—, HO2CCH2—, 2-hydroxyphenyl, 3-hydroxyphenyl, 4-hydroxyphenyl, (CH3)2NCH2—, (CH3)2CHCH(NH2)—, HOCH2CH2NH—, CH3OCH2O—, CH3OCH2CH2O—, 2-pyrrolyl, 2-pyridyl, 3-pyridyl, 4-pyridyl, 1-methyl-1,4-dihydro-3-pyridyl, 2-pyrazinyl, 2-quinolyl, 3-quinolyl, 4-quinolyl, 1-isoquinolyl, 3-isoquinolyl, 2-quinoxalinyl, a phenyl group of formula
a picolyl group selected from the group consisting of
a picolyloxy group selected from the group consisting of
a substituted pyridyl group selected from the group consisting of
and a group of formula,
wherein X and Y, the same or different, are selected from the group consisting of H, a straight alkyl group of 1 to 6 carbon atoms, a branched alkyl group of 3 to 6 carbon atoms, a cycloalkyl group of 3 to 6 carbon atoms, F, Cl, Br, I, —CF3, —OCF3, —CN, —NO2, —NR5R6, —NHCOR5, —OR5, —SR5, —COOR5, —COR5, and —CH2OH or X and Y together define an ethyleneoxy group of formula —OCH2CH2—, or —CH2CH2O—, or an alkylenedioxy group selected from the group consisting of a methylenedioxy group of formula —OCH2O—, and an ethylenedioxy group of formula —OCH2CH2O—,
wherein R1 is selected from the group consisting of a straight alkyl group of 1 to 6 carbon atoms, a branched alkyl group of 3 to 6 carbon atoms, a cycloalkylalkyl group having 3 to 6 carbon atoms in the cycloalkyl part thereof and 1 to 3 carbon atoms in the alkyl part thereof, 2-pyridyl-CH2—, 3-pyridyl-CH2—, and 4-pyridyl-CH2—,
wherein R2 is selected from the group consisting of 2-pyridyl-CH2—, 3-pyridyl-CH2—, 4-pyridyl-CH2—,
a benzenesulfonyl group of formula
a thiophenesulfonyl group of formula
a group selected from the group of
a group of formula
a group selected from the group of formula
and a group of formula R2A—CO—, R2A being selected from the group consisting of piperonyl, 2-pyrazinyl (unsubstituted or substituted with H, or an alkyl of 1 to 4 carbon atoms) and a group selected from the group of
wherein X′ and Y′, the same or different, are selected from the group consisting of H, a straight alkyl group of 1 to 6 carbon atoms, a branched alkyl group of 3 to 6 carbon atoms, a cycloalkyl group of 3 to 6 carbon atoms, F, Cl, Br, I, —CF3, —NO2, —NR5R6, —NHCOR5, —OR5, —SR5, —COOR5, —COR5, —OCF3, —CN and —CH2OH,
wherein R4 is selected from the group consisting of H, a straight alkyl group of 1 to 6 carbon atoms, a branched alkyl group of 3 to 6 carbon atoms, and a cycloalkyl group of 3 to 6 carbon atoms,
wherein R5 and R6, the same or different, are selected from the group consisting of H, a straight alkyl group of 1 to 6 carbon atoms, a branched alkyl group of 3 to 6 carbon atoms, and a cycloalkyl group of 3 to 6 carbon atoms,
wherein R3 is selected from the group consisting of a cyclohexyl group of formula
a phenyl group of formula
a diphenylmethyl group of formula IV
a naphthyl-1-CH2— group of formula V
a naphthyl-2-CH2— group of formula VI
a biphenylmethyl group of formula VII
and an anthryl-9-CH2— group of formula VIII

### Claim 2

(canceled)

### Claim 3 (depends on 1)

The compound of claim 1, wherein Cx is CH2OH or CH2OR7.

### Claim 4

A compound of formula I
or a pharmaceutically acceptable salt thereof or a stereoisomer thereof,
wherein Cx is selected from the group consisting of COOM′, CONR5R6, and CH2OR7, wherein R7 is selected from the group consisting of (HO)2P(O) and (MO)2P(O), wherein M′ is H or an alkali metal or alkaline earth metal, wherein M is an alkali metal or alkaline earth metal and a group of formula R7A—CO—, R7A being selected from the group consisting of a straight or branched alkyl group of 1 to 6 carbon atoms, a cycloalkyl group having 3 to 6 carbon atoms, a cycloalkylalkyl group having 3 to 6 carbon atoms in the cycloalkyl part thereof and 1 to 3 carbon atoms in the alkyl part thereof, an alkyloxy group of 1 to 6 carbon atom, —CH2OH, CH3O2C—, CH3O2CCH2—, Acetyl-OCH2CH2—, HO2CCH2—, 2-hydroxyphenyl, 3-hydroxyphenyl, 4-hydroxyphenyl, (CH3)2NCH2—, (CH3)2CHCH(NH2)—, HOCH2CH2NH—, CH3OCH2O—, CH3OCH2CH2O—, 2-pyrrolyl, 2-pyridyl, 3-pyridyl, 4-pyridyl, 1-methyl-1,4-dihydro-3-pyridyl, 2-pyrazinyl, 2-quinolyl, 3-quinolyl, 4-quinolyl, 1-isoquinolyl, 3-isoquinolyl, 2-quinoxalinyl, a phenyl group of formula
a picolyl group selected from the group consisting of
a picolyloxy group selected from the group consisting of
a substituted pyridyl group selected from the group consisting of
and a group of formula
wherein X and Y, the same or different, are selected from the group consisting of H, a straight alkyl group of 1 to 6 carbon atoms, a branched alkyl group of 3 to 6 carbon atoms, a cycloalkyl group of 3 to 6 carbon atoms, F, Cl, Br, I, —CF3, —OCF3, —CN, —NO2, —NR5R6, —NHCOR5, —OR5, —SR5, —COOR5, —COR5, and —CH2OH or X and Y together define an ethyleneoxy group of formula —OCH2CH2—, or —CH2CH2O—, or an alkylenedioxy group selected from the group consisting of a methylenedioxy group of formula —OCH2O—, and an ethylenedioxy group of formula —OCH2CH2O—,
wherein R1 is selected from the group consisting of a straight alkyl group of 1 to 6 carbon atoms, a branched alkyl group of 3 to 6 carbon atoms, a cycloalkylalkyl group having 3 to 6 carbon atoms in the cycloalkyl part thereof and 1 to 3 carbon atoms in the alkyl part thereof, 2-pyridyl-CH2—, 3-pyridyl-CH2—, and 4-pyridyl-CH2—,
wherein R2 is selected from the group consisting of H, a straight alkyl group of 1 to 6 carbon atoms, a branched alkyl group of 3 to 6 carbon atoms, a cycloalkyl group of 3 to 6 carbon atoms, 2-pyridyl-CH2—, 3-pyridyl-CH2—, 4-pyridyl-CH2—,
a benzenesulfonyl group of formula
a thiophenesulfonyl group of formula
a group selected from the group of
a group of formula
a group selected from the group of formula
and a group of formula R2A—CO—, R2A being selected from the group consisting of a straight or branched alkyl group of 1 to 6 carbon atoms, a cycloalkyl group having 3 to 6 carbon atoms, a cycloalkylalkyl group having 3 to 6 carbon atoms in the cycloalkyl part thereof and 1 to 3 carbon atoms in the alkyl part thereof, an alkyloxy group of 1 to 6 carbon atoms, tetrahydro-3-furanyloxy, —CH2OH, —CF3, —CH2CF3, —CH2CH2CF3, piperonyl, pyrrolidinyl, piperidinyl, 4-morpholinyl, CH3O2C—, CH3O2CCH2—, Acetyl-OCH2CH2—, HO2CCH2—, 3-hydroxyphenyl, 4-hydroxyphenyl, 4-CH3OC6H4CH2—, CH3NH—, (CH3)2N—, (CH3CH2)2N—, (CH3CH2CH2)2N—, HOCH2CH2NH—, CH3OCH2O—, CH3OCH2CH2CH2O—, C6H5CH2O—, 2-pyrrolyl, 2-pyridyl(unsubstituted or substituted), 3-pyridyl(unsubstituted or substituted), 4-pyridyl-(unsubstituted or substituted), 2-pyrazinyl (unsubstituted or substituted with H, alkyl of 1 to 4 carbon atoms), 2-quinolyl, 3-quinolyl, 4-quinolyl, 1-isoquinolyl, 3-isoquinolyl, 2-quinoxalinyl,
a phenyl group of formula
a picolyl group selected from the group consisting of
a picolylamine group selected from the group
a picolyloxy group selected from the group consisting of
a substituted pyridyl group selected from the group consisting of
a group selected from the group consisting of
wherein X′ and Y′, the same or different, are selected from the group consisting of H, a straight alkyl group of 1 to 6 carbon atoms, a branched alkyl group of 3 to 6 carbon atoms, a cycloalkyl group of 3 to 6 carbon atoms, F, Cl, Br, I, —CF3, —NO2, —NR5R6, —NHCOR5, —OR5, —SR5, —COOR5, —COR5, —OCF3, —CN and —CH2OH,
and further wherein at least one of X′ or Y′ is a straight alkyl group of 1 to 6 carbon atoms, a branched alkyl group of 3 to 6 carbon atoms, or a cycloalkyl group of 3 to 6 carbon atoms,
wherein R4 is selected from the group consisting of H, a straight alkyl group of 1 to 6 carbon atoms, a branched alkyl group of 3 to 6 carbon atoms, and a cycloalkyl group of 3 to 6 carbon atoms,
wherein R5 and R6, the same or different, are selected from the group consisting of H, a straight alkyl group of 1 to 6 carbon atoms, a branched alkyl group of 3 to 6 carbon atoms, and a cycloalkyl group of 3 to 6 carbon atoms,
wherein R3 is a phenyl group of formula

### Claim 5

A compound of formula I
or a pharmaceutically acceptable salt thereof or a stereoisomer thereof,
wherein Cx is CH2OR7, wherein R7 is selected from the group consisting of (HO)2P(O) and (MO)2P(O),
wherein M is an alkali metal or alkaline earth metal,
wherein X and Y, the same or different, are selected from the group consisting of H, a straight alkyl group of 1 to 6 carbon atoms, a branched alkyl group of 3 to 6 carbon atoms, a cycloalkyl group of 3 to 6 carbon atoms, F, Cl, Br, I, —CF3, —OCF3, —CN, —NO2, —NR5R6, —NHCOR5, —OR5, —SR5, —COOR5, —COR5, and —CH2OH or X and Y together define an ethyleneoxy group of formula —OCH2CH2—, or —CH2CH2O—, or an alkylenedioxy group selected from the group consisting of a methylenedioxy group of formula —OCH2O—, and an ethylenedioxy group of formula —OCH2CH2O—,
wherein R1 is selected from the group consisting of a straight alkyl group of 1 to 6 carbon atoms, a branched alkyl group of 3 to 6 carbon atoms, a cycloalkylalkyl group having 3 to 6 carbon atoms in the cycloalkyl part thereof and 1 to 3 carbon atoms in the alkyl part thereof, 2-pyridyl-CH2—, 3-pyridyl-CH2—, and 4-pyridyl-CH2—,
wherein R2 is selected from the group consisting of H, a straight alkyl group of 1 to 6 carbon atoms, a branched alkyl group of 3 to 6 carbon atoms, a cycloalkyl group of 3 to 6 carbon atoms, 2-pyridyl-CH2—, 3-pyridyl-CH2—, 4-pyridyl-CH2—,
a benzenesulfonyl group of formula
a thiophenesulfonyl group of formula
a group selected from the group of
a group of formula
a group selected from the group of formula
and a group of formula R2A—CO—, R2A being selected from the group consisting of a straight or branched alkyl group of 1 to 6 carbon atoms, a cycloalkyl group having 3 to 6 carbon atoms, a cycloalkylalkyl group having 3 to 6 carbon atoms in the cycloalkyl part thereof and 1 to 3 carbon atoms in the alkyl part thereof, an alkyloxy group of 1 to 6 carbon atoms, tetrahydro-3-furanyloxy, —CH2OH, —CF3, —CH2CF3, —CH2CH2CF3, piperonyl, pyrrolidinyl, piperidinyl, 4-morpholinyl, CH3O2C—, CH3O2CCH2—, Acetyl-OCH2CH2—, HO2CCH2—, 3-hydroxyphenyl, 4-hydroxyphenyl, 4-CH3OC6H4CH2—, CH3NH—, (CH3)2N—, (CH3CH2)2N—, (CH3CH2CH2)2N—, HOCH2CH2NH—, CH3OCH2O—, CH3OCH2CH2O—, C6H5CH2O—, 2-pyrrolyl, 2-pyridyl(unsubstituted or substituted), 3-pyridyl(unsubstituted or substituted), 4-pyridyl-(unsubstituted or substituted), 2-pyrazinyl (unsubstituted or substituted with H, alkyl of 1 to 4 carbon atoms), 2-quinolyl, 3-quinolyl, 4-quinolyl, 1-isoquinolyl, 3-isoquinolyl, 2-quinoxalinyl,
a phenyl group of formula
a picolyl group selected from the group consisting of
a picolylamine group selected from the group
a picolyloxy group selected from the group consisting of
a substituted pyridyl group selected from the group consisting of
a group selected from the group consisting of
wherein X′ and Y′, the same or different, are selected from the group consisting of H, a straight alkyl group of 1 to 6 carbon atoms, a branched alkyl group of 3 to 6 carbon atoms, a cycloalkyl group of 3 to 6 carbon atoms, F, Cl, Br, I, —CF3, —NO2, —NR5R6, —NHCOR5, —OR5, —SR5, —COOR5, —COR5, —OCF3, —CN and —CH2OH,
wherein R4 is selected from the group consisting of H, a straight alkyl group of 1 to 6 carbon atoms, a branched alkyl group of 3 to 6 carbon atoms, and a cycloalkyl group of 3 to 6 carbon atoms,
wherein R5 and R6, the same or different, are selected from the group consisting of H, a straight alkyl group of 1 to 6 carbon atoms, a branched alkyl group of 3 to 6 carbon atoms, and a cycloalkyl group of 3 to 6 carbon atoms,
wherein R3 is a phenyl group of formula

### Claim 6 (depends on 1)

The compound of claim 1, wherein R3 is (C6H5)2CH—, 1-naphthyl-CH2—, or 2-naphthyl-CH2—.

### Claim 7

A compound of formula IA
or a pharmaceutically acceptable salt thereof or a stereoisomer thereof,
wherein Cx is selected from the group consisting of CH2OH, COOM′, CONH2, CONR5R6, and CH2OR7, wherein R7 is selected from the group consisting of (HO)2P(O) and (MO)2P(O), wherein M′ is H or an alkali metal or alkaline earth metal, wherein M is an alkali metal or alkaline earth metal and a group of formula R7A—CO—, R7A being selected from the group consisting of a straight or branched alkyl group of 1 to 6 carbon atoms, a cycloalkyl group having 3 to 6 carbon atoms, a cycloalkylalkyl group having 3 to 6 carbon atoms in the cycloalkyl part thereof and 1 to 3 carbon atoms in the alkyl part thereof, an alkyloxy group of 1 to 6 carbon atom, —CH2OH, CH3O2C—, CH3O2CCH2—, Acetyl-OCH2CH2—, HO2CCH2—, 2-hydroxyphenyl, 3-hydroxyphenyl, 4-hydroxyphenyl, (CH3)2NCH2—, (CH3)2CHCH(NH2)—, HOCH2CH2NH—, CH3OCH2O—, CH3OCH2CH2O—, 2-pyrrolyl, 2-pyridyl, 3-pyridyl, 4-pyridyl, 1-methyl-1,4-dihydro-3-pyridyl, 2-pyrazinyl, 2-quinolyl, 3-quinolyl, 4-quinolyl, 1-isoquinolyl, 3-isoquinolyl, 2-quinoxalinyl,
a phenyl group of formula
a picolyl group selected from the group consisting of
a picolyloxy group selected from the group consisting of
a substituted pyridyl group selected from the group consisting of
and a group of formula,
wherein X and Y, the same or different, are selected from the group consisting of H, a straight alkyl group of 1 to 6 carbon atoms, a branched alkyl group of 3 to 6 carbon atoms, a cycloalkyl group of 3 to 6 carbon atoms, F, Cl, Br, I, —CF3, —OCF3, —CN, —NO2, —NR5R6, —NHCOR5, —OR5, —SR5, —COOR5, —COR5, and —CH2OH or X and Y together define an ethyleneoxy group of formula —OCH2CH2— or —CH2CH2O—, or an alkylenedioxy group selected from the group consisting of a methylenedioxy group of formula —OCH2O— and an ethylenedioxy group of formula —OCH2CH2O—,
wherein R1 is selected from the group consisting of a straight alkyl group of 1 to 6 carbon atoms, a branched alkyl group of 3 to 6 carbon atoms, a cycloalkylalkyl group having 3 to 6 carbon atoms in the cycloalkyl part thereof and 1 to 3 carbon atoms in the alkyl part thereof, 2-pyridyl-CH2—, 3-pyridyl-CH2— and 4-pyridyl-CH2—,
wherein R2 is selected from the group consisting of H, a straight alkyl group of 1 to 6 carbon atoms, a branched alkyl group of 3 to 6 carbon atoms, a cycloalkyl group of 3 to 6 carbon atoms, 2-pyridyl-CH2—, 3-pyridyl-CH2—, 4-pyridyl-CH2—,
a benzenesulfonyl group of formula
a thiophenesulfonyl group of formula
a group selected from the group of
a group of formula
and a group of formula R2A—CO—, R2A being selected from the group consisting of a straight or branched alkyl group of 1 to 6 carbon atoms, a cycloalkyl group having 3 to 6 carbon atoms, a cycloalkylalkyl group having 3 to 6 carbon atoms in the cycloalkyl part thereof and 1 to 3 carbon atoms in the alkyl part thereof, an alkyloxy group of 1 to 6 carbon atoms, tetrahydro-3-furanyloxy, —CH2OH, —CF3, —CH2CF3, —CH2CH2CF3, piperonyl, pyrrolidinyl, piperidinyl, 4-morpholinyl, CH3O2C—, CH3O2CCH2—, Acetyl-OCH2CH2—, HO2CCH2—, 3-hydroxyphenyl, 4-hydroxyphenyl, 4-CH3OC6H4CH2—, CH3NH—, (CH3)2N—, (CH3CH2)2N—, (CH3CH2CH2)2N—, HOCH2CH2NH—, CH3OCH2O—, CH3OCH2CH2O—, C6H5CH2O—, 2-pyrrolyl, 2-pyridyl-(unsubstituted or substituted), 3-pyridyl-(unsubstituted or substituted), 4-pyridyl-(unsubstituted or substituted), 2-pyrazinyl (unsubstituted or substituted with H, or an alkyl of 1 to 4 carbon atoms), 2-quinolyl, 3-quinolyl, 4-quinolyl, 1-isoquinolyl, 3-isoquinolyl, 2-quinoxalinyl,
a phenyl group of formula
a picolyl group selected from the group consisting of
a picolylamine group selected from the group
a picolyloxy group selected from the group consisting of
a substituted pyridyl group selected from the group consisting of
a group selected from the group consisting of
wherein X′ and Y′, the same or different, are selected from the group consisting of H, a straight alkyl group of 1 to 6 carbon atoms, a branched alkyl group of 3 to 6 carbon atoms, a cycloalkyl group of 3 to 6 carbon atoms, F, Cl, Br, I, —CF3, —NO2, —NR5R6, —NHCOR5, —OR5, —SR5, —COOR5, —COR5, —N, —OCF3 and —CH2OH,
wherein R4 is selected from the group consisting of H, a straight alkyl group of 1 to 6 carbon atoms, a branched alkyl group of 3 to 6 carbon atoms, and a cycloalkyl group of 3 to 6 carbon atoms,
wherein R5 and R6, the same or different, are selected from the group consisting of H, a straight alkyl group of 1 to 6 carbon atoms, a branched alkyl group of 3 to 6 carbon atoms, and a cycloalkyl group of 3 to 6 carbon atoms.

### Claim 8 (depends on 7)

The compound of claim 7, wherein Cx is selected from the group consisting of COOH, and CONR5R6.

### Claim 9 (depends on 7)

The compound of claim 7, wherein R2 is selected from the group consisting of 2-pyridyl-CH2—, 3-pyridyl-CH2—, 4-pyridyl-CH2—,
a benzenesulfonyl group of formula
a thiophenesulfonyl group of formula
a group selected from the group of
a group of formula
a group selected from the group of formula
and a group of formula R2A—CO—, R2A being selected from the group consisting of piperonyl, NR5R6(CH2)m—O—, 2-pyrazinyl (unsubstituted or substituted with H, or an alkyl of 1 to 4 carbon atoms), and a group selected from the group

### Claim 10 (depends on 9)

The compound of claim 9, wherein R2 is selected from the group consisting of a benzenesulfonyl group of formula
a thiophenesulfonyl group of formula
a group selected from the group of
a group of formula
a group selected from the group of formula

### Claim 11

A compound of formula IB
or a pharmaceutically acceptable salt thereof or a stereoisomer thereof,
wherein Cx is selected from the group consisting of CH2OH, COOM′, CONH2, CONR5R6, and CH2OR7, wherein R7 is selected from the group consisting of (HO)2P(O) and (MO)2P(O), wherein M′ is H or an alkali metal or alkaline earth metal, wherein M is an alkali metal or alkaline earth metal and a group of formula R7A—CO—, R7A being selected from the group consisting of a straight or branched alkyl group of 1 to 6 carbon atoms, a cycloalkyl group having 3 to 6 carbon atoms, a cycloalkylalkyl group having 3 to 6 carbon atoms in the cycloalkyl part thereof and 1 to 3 carbon atoms in the alkyl part thereof, an alkyloxy group of 1 to 6 carbon atom, —CH2OH, CH3O2C—, CH3O2CCH2—, Acetyl-OCH2CH2—, HO2CCH2—, 2-hydroxyphenyl, 3-hydroxyphenyl, 4-hydroxyphenyl, (CH3)2NCH2—, (CH3)2CHCH(NH2)—, HOCH2CH2NH—, CH3OCH2O—, CH3OCH2CH2O—, 2-pyrrolyl, 2-pyridyl, 3-pyridyl, 4-pyridyl, 1-methyl-1,4-dihydro-3-pyridyl, 2-pyrazinyl, 2-quinolyl, 3-quinolyl, 4-quinolyl, 1-isoquinolyl, 3-isoquinolyl, 2-quinoxalinyl, a phenyl group of formula
a picolyl group selected from the group consisting of
a picolyloxy group selected from the group consisting of
a substituted pyridyl group selected from the group consisting of
and a group of formula
wherein X and Y, the same or different, are selected from the group consisting of H, a straight alkyl group of 1 to 6 carbon atoms, a branched alkyl group of 3 to 6 carbon atoms, a cycloalkyl group of 3 to 6 carbon atoms, F, Cl, Br, I, —CF3, —OCF3, —CN, —NO2, —NR5R6, —NHCOR5, —OR5, —SR5, —COOR5, —COR5, and —CH2OH or X and Y together define an ethylenoxy group of formula —CH2CH2O— or —CH2CH2O— or an alkylenedioxy group selected from the group consisting of a methylenedioxy group of formula —OCH2O— and an ethylenedioxy group of formula —OCH2CH2O—,
wherein R1 is selected from the group consisting of a straight alkyl group of 1 to 6 carbon atoms, a branched alkyl group of 3 to 6 carbon atoms, a cycloalkylalkyl group having 3 to 6 carbon atoms in the cycloalkyl part thereof and 1 to 3 carbon atoms in the alkyl part thereof, 2-pyridyl-CH2—, 3-pyridyl-CH2—, and 4-pyridyl-CH2—,
wherein R2 is selected from the group consisting of piperonyl-CO—, 2-pyridyl-CO—, 3-pyridyl-CO—, 4-pyridyl-CO—, 2-pyrazinyl-CO— (unsubstituted or substituted with H, or an alkyl of 1 to 4 carbon atoms), a carboxyphenyl group of formula
and a pyridyl-CO— group selected from the group consisting of
wherein at least one of V and W being a straight alkyl group of 1 to 6 carbon atoms, a branched alkyl group of 3 to 6 carbon atoms, a cycloalkyl group of 3 to 6 carbon atoms and the other of V and W being, H, a straight alkyl group of 1 to 6 carbon atoms, a branched alkyl group of 3 to 6 carbon atoms, a cycloalkyl group of 3 to 6 carbon atoms, F, Cl, Br, I, —CF3, —NO2, —NR5R6, —NHCOR5, —OR5, —SR5, —COOR5, —COR5, and —CH2OH,
wherein X′ and Y′, the same or different, are selected from the group consisting of H, a straight alkyl group of 1 to 6 carbon atoms, a branched alkyl group of 3 to 6 carbon atoms, a cycloalkyl group of 3 to 6 carbon atoms, F, Cl, Br, I, —CF3, —NO2, —NR5R6, —NHCOR5, —OR5, —SR5, —COOR5, —COR5, and —CH2OH,
wherein R4 is selected from the group consisting of H, a straight alkyl group of 1 to 6 carbon atoms, a branched alkyl group of 3 to 6 carbon atoms, and a cycloalkyl group of 3 to 6 carbon atoms,
wherein R5 and R6, the same or different, are selected from the group consisting of H, a straight alkyl group of 1 to 6 carbon atoms, a branched alkyl group of 3 to 6 carbon atoms, and a cycloalkyl group of 3 to 6 carbon atoms.

### Claim 12

A compound of formula Ib
or a pharmaceutically acceptable salt thereof or a stereoisomer thereof,
wherein R7 is selected from the group consisting of (HO)2P(O) and (MO)2P(O), wherein M is an alkali metal or alkaline earth metal and a group of formula R7A—CO—, R7A being selected from the group consisting of an alkyloxy group of 1 to 6 carbon atom, —CH2OH, CH3O2C—, CH3O2CCH2—, Acetyl-OCH2CH2—, HO2CCH2—, 2-hydroxyphenyl, 3-hydroxyphenyl, 4-hydroxyphenyl, (CH3)2NCH2—, (CH3)2CHCH(NH2)—, HOCH2CH2NH—, CH3OCH2O—, CH3OCH2CH2O—, 2-pyrrolyl, 2-pyridyl, 3-pyridyl, 4-pyridyl, 1-methyl-1,4-dihydro-3-pyridyl, 2-pyrazinyl, 2-quinolyl, 3-quinolyl, 4-quinolyl, 1-isoquinolyl, 3-isoquinolyl, 2-quinoxalinyl,
a phenyl group of formula
a picolyl group selected from the group consisting of
a picolyloxy group selected from the group consisting of
a substituted pyridyl group selected from the group consisting of
and a group of formula,
wherein X and Y, the same or different, are selected from the group consisting of H, a straight alkyl group of 1 to 6 carbon atoms, a branched alkyl group of 3 to 6 carbon atoms, a cycloalkyl group of 3 to 6 carbon atoms, F, Cl, Br, I, —CF3, —OCF3, —CN, —NO2, —NR5R6, —NHCOR5, —OR5, —SR5, —COOR5, —COR5, and —CH2OH or X and Y together define an ethylenoxy group of formula —CH2CH2O— or —OCH2CH2— or an alkylenedioxy group selected from the group consisting of a methylenedioxy group of formula —OCH2O— and an ethylenedioxy group of formula —OCH2CH2O—,
wherein R1 is selected from the group consisting of a straight alkyl group of 1 to 6 carbon atoms, a branched alkyl group of 3 to 6 carbon atoms, a cycloalkylalkyl group having 3 to 6 carbon atoms in the cycloalkyl part thereof and 1 to 3 carbon atoms in the alkyl part thereof, 2-pyridyl-CH2—, 3-pyridyl-CH2— and 4-pyridyl-CH2—,
wherein R2 is selected from the group consisting of H, a straight alkyl group of 1 to 6 carbon atoms, a branched alkyl group of 3 to 6 carbon atoms, a cycloalkyl group of 3 to 6 carbon atoms, 2-pyridyl-CH2—, 3-pyridyl-CH2—, 4-pyridyl-CH2—,
a benzenesulfonyl group of formula
a thiophenesulfonyl group of formula
a group selected from the group of
a group of formula
a group selected from the group of formula
a group of formula R2A—CO—, R2A being selected from the group consisting of a straight or branched alkyl group of 1 to 6 carbon atoms, a cycloalkyl group having 3 to 6 carbon atoms, a cycloalkylalkyl group having 3 to 6 carbon atoms in the cycloalkyl part thereof and 1 to 3 carbon atoms in the alkyl part thereof, an alkyloxy group of 1 to 6 carbon atoms, tetrahydro-3-furanyloxy, —CH2OH, —CF3, —CH2CF3, —CH2CH2CF3, piperonyl, pyrrolidinyl, piperidinyl, 4-morpholinyl, CH3O2C—, CH3O2CCH2—, Acetyl-OCH2CH2—, HO2CCH2—, 3-hydroxyphenyl, 4-hydroxyphenyl, 4-CH3OC6H4CH2—, CH3NH—, (CH3)2N—, (CH3CH2)2N—, (CH3CH2CH2)2N—, HOCH2CH2NH—, CH3OCH2O—, CH3OCH2CH2O—, C6H5CH2O—, 2-pyrrolyl, 2-pyridyl, 3-pyridyl, 4-pyridyl-, 2-pyrazinyl (unsubstituted or substituted with H or an alkyl of 1 to 4 carbon atoms), 2-quinolyl, 3-quinolyl, 4-quinolyl, 1-isoquinolyl, 3-isoquinolyl, 2-quinoxalinyl, a phenyl group of formula
a picolyl group selected from the group consisting of
a picolylamine group selected from the group
a picolyloxy group selected from the group consisting of
a substituted pyridyl group selected from the group consisting of
a group selected from the group consisting of
wherein X′ and Y′, the same or different, are selected from the group consisting of H, a straight alkyl group of 1 to 6 carbon atoms, a branched alkyl group of 3 to 6 carbon atoms, a cycloalkyl group of 3 to 6 carbon atoms, F, Cl, Br, I, —CF3, —NO2, —NR5R6, —NHCOR5, —OR5, —SR5, —COOR5, —COR5, —CN, —OCF3, and —CH2OH,
wherein R4 is selected from the group consisting of H, a straight alkyl group of 1 to 6 carbon atoms, a branched alkyl group of 3 to 6 carbon atoms, and a cycloalkyl group of 3 to 6 carbon atoms, and wherein R5 and R6, the same or different, are selected from the group consisting of H, a straight alkyl group of 1 to 6 carbon atoms, a branched alkyl group of 3 to 6 carbon atoms, and a cycloalkyl group of 3 to 6 carbon atoms.

### Claim 13

A compound of formula II
or a pharmaceutically acceptable salt thereof or a stereoisomer thereof,
wherein Cx is selected from the group consisting of CH2OH, COOM′, CONH2, CONR5R6, and CH2OR7 wherein R7 is selected from the group consisting of (HO)2P(O) and (MO)2P(O), wherein M′ is H or an alkali metal or alkaline earth metal, wherein M is an alkali metal or alkaline earth metal and a group of formula R7A—CO—, R7A being selected from the group consisting of a straight or branched alkyl group of 1 to 6 carbon atoms, a cycloalkyl group having 3 to 6 carbon atoms, a cycloalkylalkyl group having 3 to 6 carbon atoms in the cycloalkyl part thereof and 1 to 3 carbon atoms in the alkyl part thereof, an alkyloxy group of 1 to 6 carbon atom, —CH2OH, CH3O2C—, CH3O2CCH2—, Acetyl-OCH2CH2—, HO2CCH2—, 2-hydroxyphenyl, 3-hydroxyphenyl, 4-hydroxyphenyl, (CH3)2NCH2—, (CH3)2CHCH(NH2)—, HOCH2CH2NH—, CH3OCH2O—, CH3OCH2CH2O—, 2-pyrrolyl, 2-pyridyl, 3-pyridyl, 4-pyridyl, 1-methyl-1,4-dihydro-3-pyridyl, 2-pyrazinyl, 2-quinolyl, 3-quinolyl, 4-quinolyl, 1-isoquinolyl, 3-isoquinolyl, 2-quinoxalinyl,
a phenyl group of formula
a picolyl group selected from the group consisting of
a picolyloxy group selected from the group consisting of
a substituted pyridyl group selected from the group consisting of
and a group of formula,
wherein X and Y, the same or different, are selected from the group consisting of H, a straight alkyl group of 1 to 6 carbon atoms, a branched alkyl group of 3 to 6 carbon atoms, a cycloalkyl group of 3 to 6 carbon atoms, F, Cl, Br, I, —CF3, —OCF3, —CN, —NO2, —NR5R6, —NHCOR5, —OR5, —SR5, —COOR5, —COR5, and —CH2OH or X and Y together define an ethylenoxy group of formula —CH2CH2O— or —OCH2CH2— or an alkylenedioxy group selected from the group consisting of a methylenedioxy group of formula —OCH2O— and an ethylenedioxy group of formula —OCH2CH2O—,
wherein R1 is selected from the group consisting of a straight alkyl group of 1 to 6 carbon atoms, a branched alkyl group of 3 to 6 carbon atoms, a cycloalkylalkyl group having 3 to 6 carbon atoms in the cycloalkyl part thereof and 1 to 3 carbon atoms in the alkyl part thereof, 2-pyridyl-CH2—, 3-pyridyl-CH2—, and 4-pyridyl-CH2—,
wherein R2 is selected from the group consisting of H, a straight alkyl group of 1 to 6 carbon atoms, a branched alkyl group of 3 to 6 carbon atoms, a cycloalkyl group of 3 to 6 carbon atoms, 2-pyridyl-CH2—, 3-pyridyl-CH2—, 4-pyridyl-CH2—,
a benzenesulfonyl group of formula
a thiophenesulfonyl group of formula
a group selected from the group of
a group of formula
a group selected from the group of formula
and a group of formula R2A—CO—, R2A being selected from the group consisting of a straight or branched alkyl group of 1 to 6 carbon atoms, a cycloalkyl group having 3 to 6 carbon atoms, a cycloalkylalkyl group having 3 to 6 carbon atoms in the cycloalkyl part thereof and 1 to 3 carbon atoms in the alkyl part thereof, an alkyloxy group of 1 to 6 carbon atoms, tetrahydro-3-furanyloxy, —CH2OH, —CF3, —CH2CF3, —CH2CH2CF3, piperonyl, pyrrolidinyl, piperidinyl, 4-morpholinyl, CH3O2C—, CH3O2CCH2—, Acetyl-OCH2CH2—, HO2CCH2—, 3-hydroxyphenyl, 4-hydroxyphenyl, 4-CH3OC6H4CH2—, CH3NH—, (CH3)2N—, (CH3CH2)2N—, (CH3CH2CH2)2N—, HOCH2CH2NH—, CH3OCH2O—, CH3OCH2CH2O—, C6H5CH2O—, 2-pyrrolyl, 2-pyridyl (unsubstituted or substituted), 3-pyridyl (unsubstituted or substituted), 4-pyridyl-(unsubstituted or substituted), 2-pyrazinyl (unsubstituted or substituted with H, or an alkyl of 1 to 4 carbon atoms), 2-quinolyl, 3-quinolyl, 4-quinolyl, 1-isoquinolyl, 3-isoquinolyl, 2-quinoxalinyl,
a phenyl group of formula
a picolyl group selected from the group consisting of
a picolylamine group selected from the group
a picolyloxy group selected from the group consisting of
a substituted pyridyl group selected from the group consisting of
a group selected from the group consisting of
wherein X′ and Y′, the same or different, are selected from the group consisting of H, a straight alkyl group of 1 to 6 carbon atoms, a branched alkyl group of 3 to 6 carbon atoms, a cycloalkyl group of 3 to 6 carbon atoms, F, Cl, Br, I, —CF3, —NO2, —NR5R6, —NHCOR5, —OR5, —SR5, —COOR5, —COR5, —CN, —OCF3 and —CH2OH,
wherein R4 is selected from the group consisting of H, a straight alkyl group of 1 to 6 carbon atoms, a branched alkyl group of 3 to 6 carbon atoms, and a cycloalkyl group of 3 to 6 carbon atoms,
wherein R5 and R6, the same or different, are selected from the group consisting of H, a straight alkyl group of 1 to 6 carbon atoms, a branched alkyl group of 3 to 6 carbon atoms, and a cycloalkyl group of 3 to 6 carbon atoms,
wherein R8 is selected from the group consisting of
a group selected from the group of
a group selected from the group of
a group of formula
and a group of formula
wherein R3 is selected from the group consisting of
a phenyl group of formula
a diphenylmethyl group of formula IV
a naphthyl-1-CH2— group of formula V
a naphthyl-2-CH2— group of formula VI
a biphenylmethyl group of formula VII
and an anthryl-9-CH2— group of formula VIII

### Claim 14

A compound of formula I
or a pharmaceutically acceptable salt thereof or a stereoisomer thereof,
wherein Cx is CH2OH,
wherein X and Y, the same or different, are selected from the group consisting of H, a straight alkyl group of 1 to 6 carbon atoms, a branched alkyl group of 3 to 6 carbon atoms, a cycloalkyl group of 3 to 6 carbon atoms, F, Cl, Br, I, —CF3, —OCF3, —CN, —NO2, —NR5R6, —NHCOR5, —OR5, —SR5, —COOR5, —COR5, and —CH2OH or X and Y together define an ethyleneoxy group of formula —OCH2CH2—, or —CH2CH2O—, or an alkylenedioxy group selected from the group consisting of a methylenedioxy group of formula —OCH2O—, and an ethylenedioxy group of formula —OCH2CH2O—,
wherein R1 is selected from the group consisting of 2-pyridyl-CH2—, 3-pyridyl-CH2—, and 4-pyridyl-CH2—,
wherein R2 is selected from the group consisting of H, a straight alkyl group of 1 to 6 carbon atoms, a branched alkyl group of 3 to 6 carbon atoms, a cycloalkyl group of 3 to 6 carbon atoms, 2-pyridyl-CH2—, 3-pyridyl-CH2—, 4-pyridyl-CH2—,
a benzenesulfonyl group of formula
a thiophenesulfonyl group of formula
a group selected from the group of
a group of formula
a group selected from the group of formula
and a group of formula R2A—CO—, R2A being selected from the group consisting of a straight or branched alkyl group of 1 to 6 carbon atoms, a cycloalkyl group having 3 to 6 carbon atoms, a cycloalkylalkyl group having 3 to 6 carbon atoms in the cycloalkyl part thereof and 1 to 3 carbon atoms in the alkyl part thereof, an alkyloxy group of 1 to 6 carbon atoms, tetrahydro-3-furanyloxy, —CH2OH, —CF3, —CH2CF3, —CH2CH2CF3, piperonyl, pyrrolidinyl, piperidinyl, 4-morpholinyl, CH3O2C—, CH3O2CCH2—, Acetyl-OCH2CH2—, HO2CCH2—, 3-hydroxyphenyl, 4-hydroxyphenyl, 4-CH3OC6H4CH2—, CH3NH—, (CH3)2N—, (CH3CH2)2N—, (CH3CH2CH2)2N—, HOCH2CH2NH—, CH3OCH2O—, CH3OCH2CH2O—, C6H5CH2O—, 2-pyrrolyl, 2-pyridyl(unsubstituted or substituted), 3-pyridyl(unsubstituted or substituted), 4-pyridyl-(unsubstituted or substituted), 2-pyrazinyl (unsubstituted or substituted with H, alkyl of 1 to 4 carbon atoms), 2-quinolyl, 3-quinolyl, 4-quinolyl, 1-isoquinolyl, 3-isoquinolyl, 2-quinoxalinyl,
a phenyl group of formula
a picolyl group selected from the group consisting of
a picolylamine group selected from the group
a picolyloxy group selected from the group consisting of
a substituted pyridyl group selected from the group consisting of
a group selected from the group consisting of
wherein X′ and Y′, the same or different, are selected from the group consisting of H, a straight alkyl group of 1 to 6 carbon atoms, a branched alkyl group of 3 to 6 carbon atoms, a cycloalkyl group of 3 to 6 carbon atoms, F, Cl, Br, I, —CF3, —NO2, —NR5R6, —NHCOR5, —OR5, —SR5, —COOR5, —COR5, —OCF3, —CN and —CH2OH,
and further wherein at least one of X′ or Y′ is a straight alkyl group of 1 to 6 carbon atoms, a branched alkyl group of 3 to 6 carbon atoms, or a cycloalkyl group of 3 to 6 carbon atoms,
wherein R4 is selected from the group consisting of H, a straight alkyl group of 1 to 6 carbon atoms, a branched alkyl group of 3 to 6 carbon atoms, and a cycloalkyl group of 3 to 6 carbon atoms,
wherein R5 and R6, the same or different, are selected from the group consisting of H, a straight alkyl group of 1 to 6 carbon atoms, a branched alkyl group of 3 to 6 carbon atoms, and a cycloalkyl group of 3 to 6 carbon atoms,
wherein R3 is selected from the group consisting of a cyclohexyl group of formula
a phenyl group of formula
a diphenylmethyl group of formula IV
a naphthyl-1-CH2— group of formula V
a naphthyl-2-CH2— group of formula VI
a biphenylmethyl group of formula VII
and an anthryl-9-CH2— group of formula VIII

### Claim 15

A compound of formula I
or a pharmaceutically acceptable salt thereof or a stereoisomer thereof,
wherein Cx is CH2OH,
wherein X and Y, the same or different, are selected from the group consisting of H, a straight alkyl group of 1 to 6 carbon atoms, a branched alkyl group of 3 to 6 carbon atoms, a cycloalkyl group of 3 to 6 carbon atoms, F, Cl, Br, I, —CF3, —OCF3, —CN, —NO2, —NR5R6, —NHCOR5, —OR5, —SR5, —COOR5, —COR5, and —CH2OH or X and Y together define an ethyleneoxy group of formula —OCH2CH2—, or —CH2CH2O—, or an alkylenedioxy group selected from the group consisting of a methylenedioxy group of formula —OCH2O—, and an ethylenedioxy group of formula —OCH2CH2O—,
wherein R1 is selected from the group consisting of a straight alkyl group of 1 to 6 carbon atoms, a branched alkyl group of 3 to 6 carbon atoms, a cycloalkylalkyl group having 3 to 6 carbon atoms in the cycloalkyl part thereof and 1 to 3 carbon atoms in the alkyl part thereof, 2-pyridyl-CH2—, 3-pyridyl-CH2—, and 4-pyridyl-CH2—,
wherein R2 is selected from the group consisting of -2-pyridyl-CH2—, 3-pyridyl-CH2—, 4-pyridyl-CH2—,
a benzenesulfonyl group of formula
a thiophenesulfonyl group of formula
a group selected from the group of
a group of formula
a group selected from the group of formula
and a group of formula R2A—CO—, R2A being selected from the group consisting of a straight or branched alkyl group of 1 to 6 carbon atoms, a cycloalkyl group having 3 to 6 carbon atoms, a cycloalkylalkyl group having 3 to 6 carbon atoms in the cycloalkyl part thereof and 1 to 3 carbon atoms in the alkyl part thereof, an alkyloxy group of 1 to 6 carbon atoms, tetrahydro-3-furanyloxy, —CH2OH, —CF3, —CH2CF3, —CH2CH2CF3, piperonyl, pyrrolidinyl, piperidinyl, 4-morpholinyl, CH3O2C—, CH3O2CCH2—, Acetyl-OCH2CH2—, HO2CCH2—, 3-hydroxyphenyl, 4-hydroxyphenyl, 4-CH3OC6H4CH2—, CH3NH—, (CH3)2N—, (CH3CH2)2N—, (CH3CH2CH2)2N—, HOCH2CH2NH—, CH3OCH2O—, CH3OCH2CH2O—, C6H5CH2O—, 2-pyrrolyl, 2-pyridyl(unsubstituted or substituted), 3-pyridyl(unsubstituted or substituted), 4-pyridyl-(unsubstituted or substituted), 2-pyrazinyl (unsubstituted or substituted with H, alkyl of 1 to 4 carbon atoms), 2-quinolyl, 3-quinolyl, 4-quinolyl, 1-isoquinolyl, 3-isoquinolyl, 2-quinoxalinyl,
a phenyl group of formula
a picolyl group selected from the group consisting of
a picolylamine group selected from the group
a picolyloxy group selected from the group consisting of
a substituted pyridyl group selected from the group consisting of
a group selected from the group consisting of
wherein X′ and Y′, the same or different, are selected from the group consisting of H, a straight alkyl group of 1 to 6 carbon atoms, a branched alkyl group of 3 to 6 carbon atoms, a cycloalkyl group of 3 to 6 carbon atoms, F, Cl, Br, I, —CF3, —NO2, —NR5R6, —NHCOR5, —OR5, —SR5, —COOR5, —COR5, —OCF3, —CN and —CH2OH,
and further wherein at least one of X′ or Y′ is a straight alkyl group of 1 to 6 carbon atoms, a branched alkyl group of 3 to 6 carbon atoms, or a cycloalkyl group of 3 to 6 carbon atoms,
wherein R4 is selected from the group consisting of H, a straight alkyl group of 1 to 6 carbon atoms, a branched alkyl group of 3 to 6 carbon atoms, and a cycloalkyl group of 3 to 6 carbon atoms,
wherein R5 and R6, the same or different, are selected from the group consisting of H, a straight alkyl group of 1 to 6 carbon atoms, a branched alkyl group of 3 to 6 carbon atoms, and a cycloalkyl group of 3 to 6 carbon atoms,
wherein R3 selected from the group consisting of a cyclohexyl group of formula
a phenyl group of formula
a diphenylmethyl group of formula IV
a naphthyl-1-CH2— group of formula V
a naphthyl-2-CH2— group of formula VI
a biphenylmethyl group of formula VII
and an anthryl-9-CH2— group of formula VIII

### Claim 16 (depends on 1)

The compound of claim 1, wherein R3 is a cyclohexyl group of the formula

### Claim 17 (depends on 1)

The compound of claim 1, wherein R3 is a phenyl group of the formula

### Claim 18 (depends on 16)

The compound of claim 16, wherein Cx is CONR5R6.

### Claim 19 (depends on 18)

The compound of claim 18, wherein R5 and R6 are H.