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US 2014/0275502 A1Published application
Process for the preparation of certain triaryl rhamnose carbamates
AssigneeDow AgroSciences LLC
InventorsNatalie C. GIAMPIETRO, Lawrence C. CREEMER, Gary D. CROUSE
Life of this patent
Estimating the term…
Abstract
Aryl boronic esters and boronic acids containing the rhamnose carbamate moiety are coupled to a triazole with an appropriate leaving group, generating a 4-triazolylphenyl carbamate in good yield and without cleavage of the carbamate linkage.
Claims11
A process for preparing triaryl rhamnose carbamates of the formula (I),
- wherein
- R, R1 and R2 independently represent C1-C4 alkyl, C3-C4 alkenyl or C1-C4 fluoroalkyl, and
- Z represents a furanyl, phenyl, pyridazinyl, pyridyl, pyrimidinyl or thienyl group, unsubstituted or substituted with one or more substituents independently selected from F, Cl, C1-C6 alkyl, C1-C6 haloalkyl, C1-C6 haloalkoxy or C1-C6 haloalkylthio;
- which comprises contacting a substituted triazole of formula (II)
- wherein
- Y represents Cl, Br, I, OSO2CF3, OSO2CH3 or OSO2C6H4CH3, and
- Z is as previously defined
- with a boronic acid or ester of the formula (III)
- wherein
- R, R1 and R2 are as previously defined, and
- R3 and R4 independently represent H, C1-C4 alkyl, or when taken together form an ethylene or propylene group optionally substituted with from one to four CH3 groups,
- in an ether solvent in the presence of tetrakis(triphenylphosphine)palladium(0) and from about 1 to about 2 equivalents of an aqueous alkali metal carbonate at a temperature from about 50° C. to about 100° C.
9 more elements
A boronic acid or ester of the formula (III)
- wherein
- R, R1 and R2 independently represent C1-C4 alkyl, C3-C4 alkenyl or C1-C4 fluoroalkyl, and
- R3 and R4 independently represent H, C1-C4 alkyl, or when taken together form an ethylene or propylene group optionally substituted with from one to four CH3 groups.
A process for preparing a boronic ester of the formula (IIIa)
- wherein
- R, R1 and R2 independently represent C1-C4 alkyl, C3-C4 alkenyl or C1-C4 fluoroalkyl, and
- R3a and R4a independently represent C1-C4 alkyl, or when taken together form an ethylene or propylene group optionally substituted with from one to four CH3 groups, which comprises
- a) contacting p-bromophenyl isocyanate
- with a tetrahydropyran-2-ol of formula (IV)
- wherein
- R, R1 and R2 independently represent C1-C4 alkyl, C3-C4 alkenyl or C1-C4 fluoroalkyl,
- in a polar aprotic solvent in the presence of cesium carbonate (Cs2CO3) to form a carbamate of formula (V)
- wherein R, R1 and R2 are as previously defined, and
- b) contacting the carbamate of formula (V) with a diboron compound of formula (VI)
- wherein R3a and R4a are as previously defined,
- in a polar aprotic solvent in the presence of a palladium catalyst and an alkali metal or alkaline earth metal acetate.
9 more elements
A process for preparing a boronic ester of the formula (IIIa)
- wherein
- R, R1 and R2 independently represent C1-C4 alkyl, C3-C4 alkenyl or C1-C4 fluoroalkyl, and
- R3a and R4a independently represent C1-C4 alkyl, or when taken together form an ethylene or propylene group optionally substituted with from one to four CH3 groups,
- which comprises contacting a boronate substituted phenyl isocyanate of formula (VII)
- wherein
- R3a and R4a independently represent C1-C4 alkyl, or when taken together form an ethylene or propylene group optionally substituted with from one to four CH3 groups,
- with a tetrahydropyran-2-ol of formula (IV)
- wherein
- R, R1 and R2 independently represent C1-C4 alkyl, C3-C4 alkenyl or C1-C4 fluoroalkyl,
- in a polar aprotic solvent in the presence of Cs2CO3.
7 more elements
A substituted triazole of formula (II)
- wherein
- Y represents Cl, Br, I, OSO2CF3, OSO2CH3 or OSO2C6H4CH3, and
- Z represents a furanyl, phenyl, pyridazinyl, pyridyl, pyrimidinyl or thienyl group, unsubstituted or substituted with one or more substituents independently selected from F, Cl, C1-C6 alkyl, C1-C6 haloalkyl, C1-C6 haloalkoxy or C1-C6 haloalkylthio.
A process for preparing a substituted triazole of formula (IIa)
- wherein
- Z represents a furanyl, phenyl, pyridazinyl, pyridyl, pyrimidinyl or thienyl group, unsubstituted or substituted with one or more substituents independently selected from F, Cl, C1-C6 alkyl, C1-C6 haloalkyl, C1-C6 haloalkoxy or C1-C6 haloalkylthio,
- which comprises contacting 3-bromo-1H-1,2,4-triazole
- with a brominated or iodinated furanyl, phenyl, pyridazinyl, pyridyl, pyrimidinyl or thienyl compound, unsubstituted or substituted with one or more substituents independently selected from F, Cl, C1-C6 alkyl, C1-C6 haloalkyl, C1-C6 haloalkoxy or C1-C6 haloalkylthio of one of the following formulas
- wherein
- L represents Br or I,
- X independently represents F, Cl, C1-C6 alkyl, C1-C6 haloalkyl, C1-C6 haloalkoxy or C1-C6 haloalkylthio,
- m=0, 1, 2 or 3,
- n=0, 1, 2, 3 or 4, and
- p=0, 1, 2, 3, 4 or 5,
- in a polar aprotic solvent in the presence of a catalytic amount of a copper catalyst and at least one equivalent of an inorganic base at a temperature from ambient to about 120° C.
8 more elements
A process for preparing a substituted triazole of formula (II)
- wherein
- Y represents Cl, Br, I, OSO2CF3, OSO2CH3 or OSO2C6H4CH3, and
- Z represents a furanyl, phenyl, pyridazinyl, pyridyl, pyrimidinyl or thienyl group, unsubstituted or substituted with one or more substituents independently selected from F, Cl, C1-C6 alkyl, C1-C6 haloalkyl, C1-C6 haloalkoxy or C1-C6 haloalkylthio,
- which comprises
- a) contacting a hydrazine hydrochloride of the formula
- Z—NH—NH2.HCl
- wherein
- Z represents a furanyl, phenyl, pyridazinyl, pyridyl, pyrimidinyl or thienyl group, unsubstituted or substituted with one or more substituents independently selected from F, Cl, C1-C6 alkyl, C1-C6 haloalkyl, C1-C6 haloalkoxy or C1-C6 haloalkylthio,
- with urea in an aprotic organic solvent with a boiling point greater than 100° C. in the presence of a catalytic amount of an organic sulfonic acid at a temperature from about 100° C. to about 150° C.,
- b) further contacting the reaction mixture from step a) with a C1-C4 alkyl orthoformate and a catalytic amount of chlorosulfonic acid at a temperature from about 60° C. to about 100° C. to provide a substituted 1-H-1,2,4-triazol-3-ol of formula (VIII)
- wherein Z is as previously defined, and
- c) converting the hydroxyl group of the triazole to a Cl, Br, I, OSO2CF3, OSO2CH3 or OSO2C6H4CH3.
9 more elements
Dependencies are inferred from the claim text.