Formic Acid → 5'-fluoro-N-methyl-2'-(methylthio)acetylformanilide

Participants

Reaction Steps

A mixture of acetic anhydride (16.5 ml) and formic acid (11.2 ml) was stirred and heated at 50°-60° under nitrogen for 2 hours. The mixture was cooled to ambient temperature and 1-(4-fluoro-2-methylaminophenyl)-2-(methylthio)ethanone (4.0 g), prepared in a similar manner to that described in Example 4, added over a period of 5 minutes. The mixture was stirred at ambient temperature for 2.75 hours and then cooled in an ice/salt bath to maintain the temperature below 30° whilst, water (50 ml) was added over a period of 30 minutes. The mixture was extracted with dichloromethane (2×25 ml), the organic phases combined, washed with water (2×20 ml) and then evaporated in vacuo to give an oily product. Purification of the oily product by high performance liquid chromatography carried out using a Gilson system fitted with a 2" Dynamax silica column and eluting with dichloromethane/methanol (99:1) at 16 ml/min gave 5'-fluoro-N-methyl-2'-(methylthio)acetylformanilide in the form of a pale yellow oil.

Provenance & Evidence