# US 9,751,896 B1 · Asymmetric 7-N isatin dimer Schiff base compounds with antitumor activities and a method of preparing the same

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- Number: US 9,751,896 B1
- Document ID: US9751896B1
- Status: Granted
- Kind: B1
- Application number: 15/489,706
- Filed: 2017-04-17
- Granted: 2017-09-05
- Earliest claimed: 2016-09-30
- Assignees: Shaanxi University of Science and Technology
- Applicants: Chengyuan Liang; Minyi Jia; Danni Tian; Xuechuan Wang; Xuefeng Chen; Juan Li; Guang Tong
- Inventors: Chengyuan Liang; Minyi Jia; Danni Tian; Xuechuan Wang; Xuefeng Chen; Juan Li; Guang Tong
- Web page: https://patentgrep.com/patent/US9751896B1

## CPC

- C07D 519/00: Heterocyclic compounds containing more than one system of two or more relevant hetero rings condensed among themselves or condensed with a common carbocyclic ring system not provided for in groups C07D453/00 or C07D455/00
- A61P 35/00: Antineoplastic agents
- C07D: HETEROCYCLIC COMPOUNDS (macromolecular compounds C08)
- A61P: SPECIFIC THERAPEUTIC ACTIVITY OF CHEMICAL COMPOUNDS OR MEDICINAL PREPARATIONS

## Abstract

A compound with antitumor activities is represented by formula: R1, R2, R3, and R4 are independently hydrogen, nitro, alkoxy, halogen, unsubstituted or substituted phenyl, or unsubstituted or substituted alkyl or cycloalkyl.

## Claims

### Claim 1

A compound with antitumor activities represented by formula I:
wherein R1, R2, R3, and R4 are independently hydrogen, nitro, alkoxy, halogen, unsubstituted or substituted phenyl, substituted or substituted benzyl, unsubstituted or substituted alkyl, or unsubstituted or substituted cycloalkyl.

### Claim 2 (depends on 1)

The compound of claim 1, wherein
R1 is hydrogen, methoxy, nitro, halogen, unsubstituted or substituted alkyl, or unsubstituted or substituted cycloalkyl;
R2 is hydrogen, unsubstituted or substituted alkyl, or unsubstituted or substituted cycloalkyl;
R3 is hydrogen, methoxy, nitro, halogen, unsubstituted or substituted phenyl, or unsubstituted or substituted alkyl or cycloalkyl; and
R4 is hydrogen, methyl, unsubstituted or substituted phenyl, unsubstituted or substituted benzyl, unsubstituted or substituted alkyl, or unsubstituted or substituted cycloalkyl.

### Claim 3 (depends on 1)

The compound of claim 1, wherein the compound is selected from the group consisting of:

### Claim 4 (depends on 1)

A method of preparing the compound of claim 1, comprising:
reacting a compound of formula II with hydrazine hydrate (N2H4.H2O) in an organic solvent to obtain a compound of formula III, and
reacting the compound of formula III with a compound of formula IV in the organic solvent to obtain the compound of formula I,

### Claim 5 (depends on 4)

The method of claim 4, wherein the organic solvent is methanol, ethanol, or isopropanol.

### Claim 6 (depends on 4)

The method of claim 4, wherein the compound of formula II and hydrazine hydrate (N2H4.H2O) are heated in the organic solvent to 60-100° C. for 4 to 9 hours.

### Claim 7 (depends on 4)

The method of claim 4, wherein the compound of formula III and the compound of formula IV are heated in the organic solvent to 60-100° C. for 2 to 6 hours.

### Claim 8 (depends on 4)

The method of claim 4, further comprising:
recrystallizing the compound of formula I in methanol, ethanol, or isopropanol.

### Claim 9 (depends on 4)

The method of claim 4, wherein a molar ratio of the compound of formula II and hydrazine hydrate (N2H4.H2O) is 1:1 to 1:2.5.

### Claim 10 (depends on 9)

The method of claim 9, wherein the molar ratio of the compound of formula II and hydrazine hydrate (N2H4.H2O) is 1:1.5 to 1:2.

### Claim 11 (depends on 4)

The method of claim 4, wherein a molar ratio of the compound of formula III and the compound of formula IV is 1:1 to 1:1.5.