# US 2017/0362197 A1 · Fluoroquinolone carboxylic acid compounds and use thereof for the preparation of besifloxacin hydrochloride

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- Number: US 2017/0362197 A1
- Document ID: US20170362197A1
- Status: Published application
- Kind: A1
- Application number: 15/543,073
- Filed: 2016-01-28
- Published: 2017-12-21
- Earliest claimed: 2015-01-28
- Assignees: Mankind Research Centre
- Applicants: Mankind Research Centre
- Inventors: Jigar Bhavsar; Bhuwan Bhashkar; Anil Kumar
- Web page: https://patentgrep.com/patent/US20170362197A1

## CPC

- C07D 401/04: directly linked by a ring-member-to-ring-member bond
- C07D: HETEROCYCLIC COMPOUNDS (macromolecular compounds C08)

## Abstract

The present invention relates to novel fluoroquinolone carboxylic acid compounds and derivatives of Formula-I, and their salts wherein, R represents H or halogen. The present invention also relates to the use of novel fluoroquinolone carboxylic acid compounds and derivatives of Formula-I for preparation of Besifloxacin hydrochloride.

## Claims

### Claim 1

Fluoroquinolone carboxylic acid compounds and derivatives of Formula-I, and salts thereof;
wherein, R is hydrogen or a halogen.

### Claim 2 (depends on 1)

Fluoroquinolone carboxylic acid compounds of Formula-I according to claim 1, having structural Formula-A and salts thereof;

### Claim 3 (depends on 1)

Fluoroquinolone carboxylic acid compounds of Formula-I and salts thereof according to claim 1, wherein said carboxylic acid compounds are selected from:

### Claim 4 (depends on 1)

Fluoroquinolone carboxylic acid compounds according to claim 1, wherein said carboxylic acid compounds are R-enantiomers.

### Claim 5 (depends on 1)

Fluoroquinolone carboxylic acid compounds according to claim 1, wherein said carboxylic acid compounds are used as intermediate in preparation of Besifloxacin hydrochloride.

### Claim 6

A process for preparation of Fluoroquinolone carboxylic acid compounds and derivatives of Formula-I and salts thereof;
wherein, R represents hydrogen or halogen;
the process comprising:
reacting Schiff base of Formula-XIII with 8-chloro-1-cyclopropyl-6,7-difluoro-4-oxo-1,4-dihydroquinoline-3-carboxylic acid of Formula-VII;
wherein, R is hydrogen or a halogen.

### Claim 7 (depends on 6)

The process according to claim 6, wherein the said Schiff base is prepared by reacting (R)-azepan-3-amine of Formula-XI with compound of Formula-XII;
wherein, R is hydrogen or a halogen.

### Claim 8 (depends on 7)

The process according to claim 7, wherein the said Schiff base is prepared in situ.

### Claim 9 (depends on 1)

A process for preparation of Besifloxacin hydrochloride, comprising de-protection of fluoroquinolone carboxylic acid compounds and derivatives and salts thereof, according to claim 1, in presence of aqueous hydrochloric acid to form Besifloxacin hydrochloride.

### Claim 10 (depends on 9)

The process according to claim 9, wherein the fluoroquinolone carboxylic acid compounds and derivatives and salts thereof are isolated in a solid state form before de-protection to Besifloxacin hydrochloride.

### Claim 11 (depends on 9)

The process according to claim 9, wherein the fluoroquinolone compounds and derivatives and salts thereof are in situ converted to Besifloxacin hydrochloride without isolation in a solid state form.