Carbon Dioxide → Methyl 2,2,3,3-tetrafluoro-3-(methylsulfanyl)propanoate

Participants

Reaction Steps

A slurry of 24 g (0.50 mole) of 50% NaH/mineral oil in 140 ml of dry dimethyl sulfoxide was stirred while 24 g (0.50 mole) of methyl mercaptan was distilled in over a 2 hr. period. The mixture was then stirred until gas evolution became very slow after which the mixture was allowed to stand overnight. The resulting mixture was a thick paste which was diluted with 50 ml of dimethyl sulfoxide and charged into a 400 ml metal tube along with 33 g (0.75 mole) of carbon dioxide and 50 g (0.50 mole) of tetrafluoroethylene. The tube was shaken at 100° for 4 hr. The resulting solution was treated with 69.3 g (0.55 mole) of dimethyl sulfate. After an initial exotherm (maximum temperature, 50°), the mixture was stirred for 3 hr. Product was then removed under vacuum and fractionated to afford 63.9 g (62%) of methyl 3-methylthio-2,2,3,3-tetrafluoropropionate, bp 53° (10 mm, 1.3 kPa), IR (neat): 3020, 2970, and 2860 (satd CH), 1780 (C=O), and 1250-1100 cm-1 (C--F), 1H and 19F NMR agreed with the assigned structure.

Provenance & Evidence