Oxalyl chloride → (S)-2-phenylpent-4-enoyl chloride

Participants

Reaction Steps

Combine (S)-2-phenylpent-4-enoic acid (1.53 g, 8.7 mmol), dichloromethane (10 mL), and dimethylformamide (1 drop). Add oxalyl chloride (1 mL, 11.46 mmol). After 2 hours, evaporate in vacuo to give (S)-2-phenylpent-4-enoyl chloride. Combine with toluene (10 mL) and add, with vigorous stirring, to a cooled (ice bath) aqueous solution of methylamine (2 mL, 40%). After 1 hour, partition the reaction mixture between water and dichloromethane. Separate the layers, dry the organic over MgSO4, filter, and evaporate in vacuo to give a residue. Triturate the residue with hexane to give a solid. Collect the solid by filtration and dry to give (S)-2-phenylpent-4-enoic acid, N-methyl amide: mp; 97-99° C. Rf =0.53 (silica gel, 50% ethyl acetate/hexane).

Provenance & Evidence