Dimethyl methylphosphonate → Dimethyl 2-oxo-4-(3,4-dimethoxyphenyl)butylphosphonate

Participants

Reaction Conditions

Reaction Steps

To a mixture cooled at -78° C. of 50 ml of 2.1M n-butyl lithium solution in hexane and 100 ml of tetrahydrofuran, was added dropwise 12.4 g of dimethyl methylphosphonate. The mixture was stirred at -78° C. for 30 minutes, and thereafter 22.4 g of methyl 3-(3,4-dimethoxyphenyl)propionate [synthesized from 3,4-dimethoxycinnamic acid in 2 steps: (a) esterification (HCl--CH3OH) and (b) reduction (Pd/C--H2)] and 100 ml of tetrahydrofuran were added dropwise to the mixture. Then, the reaction was continued at -78° C. for 22 hours. The reaction mixture was poured in 500 ml of saturated aqueous sodium chloride solution. After neutralization and extraction with dichloromethane, the extract was dried and concentrated to give crude product. By purification of the crude product by means of column chromatography (silica gel/hexane:ethyl acetate=1:4), 9.0 g of the above caption compound was obtained.

Provenance & Evidence