Patent ID: 8367837

Claim:
A process for the preparation of (R,S)-nicotine which comprises of: reacting 2-pyrrolidone with butanal using phosphorus pentoxide to obtain N-(1-butenyl)-2-pyrrolidone having the structure-1: (b) reacting N-(1-butenyl)-2-pyrrolidone of structure-I, with nicotinic acid ester in a polar solvent such as dimethylformamide or tetrahydrofuran in presence of a base such as sodium hydride, to obtain 1-(1-butenyl)-3-nicotinoyl-pyrrolidine-2-one having the structure-II: (c) reacting 1-(1-butenyl)-3-nicotinoyl-pyrrolidine-2-one of structure-II, with an acid such as hydrochloric acid, to effect decarboxylation, followed by reacting with a base such as sodium hydroxide, for cyclization to obtain myosmine, (d) hydrogenating myosmine using a catalyst such as palladium on carbon, to obtain (R,S)-nornicotine; and e) converting the (R,S)-nornicotine to (R,S)-nicotine by N-methylation.