Process for preparing benzofuran-2-carboxamide derivatives
AssigneeSymed Labs Limited
InventorsMohan Rao Dodda, Jithender Aadepu
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Abstract
Provided herein are novel, commercially viable and industrially advantageous processes for the preparation of benzofuran-2-carboxamide derivatives and their intermediates, or a pharmaceutically acceptable salt thereof, in high yield and purity. Provided particularly herein are novel, commercially viable and industrially advantageous processes for the preparation of vilazodone or a pharmaceutically acceptable salt thereof in high yield and purity. Provided also herein is an improved and commercially viable process for the preparation of 3-(4-hydroxybutyl)-1H-indole-5-carbonitrile, in high yield and purity, using novel intermediate compound 3-(4-hydroxybutyryl)-1H-indole-5-carbonitrile.
Claims9
A process for the preparation of a benzofuran-2-carboxamide derivative of formula I:
- or a pharmaceutically acceptable salt thereof,
- wherein R is H, a protecting group or an ‘IND-Q-’ radical,
- wherein IND is an indol-3-yl radical, a 2,3-di-hydro-1H-indol-3-yl radical, or a 2-oxo-2,3-di-hydro-1H-indol-3-yl radical, which is unsubstituted or mono- or polysubstituted by OH, OA, CN, X, COR1 or CH2R1;
- Q is selected from —(CH2)2—, —(CH2)3—, and —(CH2)4—;
- A is an alkyl group having 1 to 6 carbon atoms;
- X is F, Cl, Br or I;
- R1 is OH, OA, NH2, NHA or NA2;
- which comprises:
- amidation of a benzofuran-2-carboxylic acid ester derivative of formula II:
- or a salt thereof, wherein R is as defined in formula I, and
- R2 is methyl;
- with ammonia in a suitable solvent to produce the benzofuran-2-carboxamide compound of formula I, and optionally converting the compound of formula I obtained into a pharmaceutically acceptable salt thereof, wherein the ammonia is used in the form of aqueous ammonia or ammonia gas or ammonia saturated in an organic solvent.
Dependencies are inferred from the claim text.