Process for the preparation of risperidone
OwnerGuntu Rao, Basavapatna Kumar +1inventors
InventorsGuntu Rao, Basavapatna Kumar, Sulur Manjunatha
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Abstract
A process is provided for the preparation of risperidone of Formula (1); which process comprises reacting, in a condensation reaction, 6-fluoro-3-(4-piperidinyl)-1,2-benzisoxazole monohydrochloride of Formula (2) with 3-(2-chloroethyl)-6,7,8,9-tetrahydro-2-methyl-4H-pyrido[1,2,a]pyrimidin-4-one monohydrochloride of Formula (3).
Claims25
A process for the preparation of risperidone of Formula 1:
- which process comprises reacting, in a condensation reaction, 6-fluoro-3-(4-piperidinyl)-1,2-benzisoxazole monohydrochloride of Formula-2 with 3-(2-chloroethyl)-6,7,8,9-tetrahydro-2-methyl-4H-pyrido[1,2,a]pyrimidin-4-one monohydrochloride of Formula-3:
A process according to claim 14, wherein the pH of the aqueous acidic extract is adjusted to basic with ammonia and is further extracted into dichloromethane.
(canceled)
A process for preparing crystalline risperidone comprising crystallizing the condensed product obtained by reacting 6-fluoro-3-(4-piperidinyl)-1,2-benzisoxazole monohydrochloride with 3-(2-chloroethyl)-6,7,8,9-tetrahydro-2-methyl-4H pyrido[1,2,a]pyrimidin-4-one monohydrochloride or crude risperidone in an aqueous organic solvent.
Dependencies are inferred from the claim text.