Yield:-

Reaction Conditions:

with acetyl chloride at 0; for 12 h;Heating / reflux;

Steps:

1
Intermediate 1 methyl (4S)-4-hydroxy-D-prolinateIn a three necked flask under argon atmosphere equipped with a magnetic stir bar and a reflux condenser was placed MeOH (7 ml_). To the system was added acetyl chloride (0.898 g, 11.4 mmol) in an ice bath followed by (4S)-4-hydroxy-D-proline (1 g, 7.6 mmol). The resultant mixture was heated at reflux for 12 hours and cooled down to room temperature. Ether was added to cause precipitation and the resulting brown powder was filtered off to afford the title compound. LC-MS: m/z, 146 (M+H).

References:

GLAXO GROUP LIMITED WO2009/26197, 2009, A1 Location in patent:Page/Page column 28

FullText