1-CYCLOHEXYL-5-OXO-PYRROLIDINE-3-CARBOXYLIC ACID synthesis

Yield:6304-56-9 96%

Reaction Conditions:

at 160;

Steps:

2

Preparation 2; 1 -Cyclohexyl-4-hydroxymethyl-pyrrolidin-2-one; Place 2-methylene-succinic acid (12.0 g, 92.2 mmol) and cyclohexylamine (9.15 g, 92.2 mmol) and heat to 16O⁰C for hours. Cool to give 18.8 g (96%) of l-cyclohexyl-5- oxo-pyrrolidine-3-carboxylic acid. Charge a flask with l-cyclohexyl-S-oxo-pyrrolidine-S- carboxylic acid (16.2 g, 76.7 mmol), add methylene chloride (20 mL) and cool to O⁰C. Slowly add borane in THF (IM, 115.1 mL, 115.1 mmol) and stir for two hours at O⁰C. Quench the reaction with ice and extract with methylene chloride. Dry over sodium sulfate, filter, and concentrate. Purify by silica gel (1-5% methanol in methylene chloride) to yield 9.9 g (65%) of the title compound

References:

WO2006/49952,2006,A1 Location in patent:Page/Page column 50