Carbon Dioxide → 3-Methylthiotetrafluoropropionic acid

Participants

Reaction Steps

NaSCH3 was prepared by distilling 24 g (0.50 mol) of methyl mercaptan into a stirred suspension of 24 g (0.50 mol) of 50% NaH/mineral oil in 170 ml of dimethyl sulfoxide over a 2-hr period. The mixture was charged into a 400-ml tube with 27 g (0.6 mol) of CO2 and 50 g (0.50 mol) of tetrafluoroethylene and shaken at 50° for 8 hrs. The reaction mixture was poured into a cold solution of 300 ml of concentrated HCl in 1 liter of water, and the resulting mixture was extracted continuously with ether. Removal of volatiles from the extracts at 5 mm gave 94.6 g of 3-methylthiotetrafluoropropionic acid. This acid was stirred at 85° to 95° while a mixture of 125 ml (about 1.2 mol) of 30% H2O2 and 75 ml of acetic acid was added dropwise over 2 hrs. The mixture was stirred at 90° to 95° for 3 hrs more, then evacuated at full pump to remove volatiles.

Provenance & Evidence