# US 10,308,611 B2 · Process for the preparation of Lorcaserin hydrochloride

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- Number: US 10,308,611 B2
- Document ID: US10308611B2
- Status: Granted
- Kind: B2
- Application number: 15/741,722
- Filed: 2016-03-18
- Published: 2018-07-12
- Granted: 2019-06-04
- Earliest claimed: 2015-03-24
- Assignees: Aurobindo Pharma Ltd
- Applicants: Aurobindo Pharma Ltd
- Inventors: Sukumar Nandi; Akkina Naresh; Syam Prasad Reddy Rao Annareddy; Gona Bala Narsimha Reddy; Meenakshi Sunderam Sivakumaran
- Web page: https://patentgrep.com/patent/US10308611B2

## CPC

- C07D 223/16: Benzazepines; Hydrogenated benzazepines
- C07B 2200/13: Crystalline forms, e.g. polymorphs
- C07D: HETEROCYCLIC COMPOUNDS (macromolecular compounds C08)
- C07B: GENERAL METHODS OF ORGANIC CHEMISTRY; APPARATUS THEREFOR (preparation of carboxylic acid esters by telomerisation C07C67/47; telomerisation C08F)

## Abstract

The present invention provides a process for the preparation of crystalline Lorcaserin hydrochloride hemihydrate of Formula (Ia), which comprises, Formula (Ia) (i) providing a solution of Lorcaserin base in a solvent; (ii) if water is present, removing water from the reaction mixture; (iii) adding hydrogen chloride to the reaction mixture; (iv) combining the reaction mixture with a suitable anti-solvent; and (v) isolating the crystalline Lorcaserin hydrochloride hemihydrate of Formula (Ia).

## Claims

### Claim 1

A process for the preparation of crystalline Lorcaserin hydrochloride hemihydrate of Formula (Ia), which comprises,
(i) providing a solution of Lorcaserin base in a solvent;
(ii) adding hydrogen chloride to the reaction mixture;
(iii) combining the reaction mixture with a suitable anti-solvent; and
(iv) isolating the crystalline Lorcaserin hydrochloride hemihydrate of Formula (Ia).

### Claim 2 (depends on 1)

The process as claimed in claim 1, wherein the solvent used in step (i) is selected from the group comprising an ester, a halogenated hydrocarbon, a ketone, an aromatic hydrocarbon or a mixture thereof.

### Claim 3 (depends on 2)

The process according to claim 2, wherein the ester comprises ethyl acetate, n-propyl acetate, n-butyl acetate, isobutyl acetate, t-butyl acetate, methyl acetate; the halogenated hydrocarbon comprises dichloromethane, 1,2-dichloroethane, chloroform, carbon tetrachloride; the ketone comprises acetone, ethyl methyl ketone, diethyl ketone, methyl isobutyl ketone, methyl-pentane-2-one; and the aromatic hydrocarbon comprises toluene, m-xylene, o-xylene, p-xylene or mixtures thereof.

### Claim 4 (depends on 1)

The process as claimed in claim 1, wherein step (ii) is carried out in the presence of a solvent selected from the group comprising an ester, an alcohol or a mixtures thereof.

### Claim 5 (depends on 4)

The process as claimed in claim 4, wherein the ester is selected from the group comprising ethyl acetate, n-propyl acetate, n-butyl acetate, isobutyl acetate, t-butyl acetate, methyl acetate or mixtures thereof.

### Claim 6 (depends on 4)

The process as claimed in claim 4, wherein the alcohol is selected from the group comprising methanol, ethanol, ethylene glycol, 1-propanol, 2-propanol (isopropyl alcohol), 2-methoxyethanol, 1-butanol, 2-butanol or mixtures thereof.

### Claim 7 (depends on 1)

The process as claimed in claim 1, wherein the anti-solvent used in step (iii) comprises cyclohexane, pentane, hexane, toluene, cycloheptane, methyl cyclohexane, heptane or mixtures thereof.

### Claim 8 (depends on 1)

The process as claimed in claim 1, wherein isolation of crystalline Lorcaserin hydrochloride hemihydrate of Formula (Ia) is performed by filtration and drying.