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US 8,133,996 B2Granted
Process for the preparation of ethyl-N-(2,3-dichloro-6-nitrobenzyl)glycine hydrochloride
AssigneeCipla Limited
InventorsSrinivas Laxminarayan Pathi, Rajendra Narayanrao Kankan, Dharmaraj Ramachandra Rao
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Abstract
The invention relates to a process for the preparation of anagrelide, and for the preparation of intermediates for use in preparing anagrelide. The invention also relates to the intermediates per se, in particular compounds of Formula (V): where R constitutes a suitable leaving group, which may not be hydrogen. The R group may be selected from: (i) —SiR13, (ii) —CH2Ar, (iii) —COOR2, and (iv) sulfonates such as —SO2R3.
Claims12
A process for preparing anagrelide of Formula (II):
- which comprises:
- (i) alkylating a compound of Formula (V):
- where R is a leaving group other than hydrogen with glycine ethyl ester in a suitable solvent, using a base, to produce a compound of Formula (I′):
- (ii) converting the compound of Formula (I′) to the hydrochloride salt in a suitable solvent, to obtain compound of Formula (I):
- (iii) reducing the nitro group of Formula (I) with a suitable reducing agent to convert it to an amine of Formula (VI):
- (iv) reacting the compound of Formula (VI) with a cyanogen halide to form compound of Formula (VII):
- wherein halide is chloro, bromo or iodo;
- and
- (v) cyclising compound of Formula (VII), to form compound of Formula (II).
6 more elements
Dependencies are inferred from the claim text.