Dimethylformamide → HCID 20144443, compound

Participants

Reaction Steps

A mixture of 7-fluoro-9-oxo-3-thioxanthene carboxylic acid 10,10-dioxide (see example 6), 34.0 g (0.11 mol), and thionyl chloride, 130.9 g (1.10 mol), was heated at reflux for 2.0 hr. Dimethyl formamide, 1 ml, was added to the mixture, giving a solution which was heated at reflux overnight. The reaction was cooled, and a yellow crystalline solid, 27.85 g, was collected and washed with ether. A portion of the acid chloride, 5.0 g, was placed in concentrated NH4OH, 50 mL, and heated on a steam bath for 0.5 hr. The solid was filtered and washed with H2O and acetone to give 3.82 g of the amide. A small amount of the amide was recrystallized from DMF:MeOH/75:25 to provide 0.3 g of a light yellow crystalline 7-fluoro-9-oxothioxanthene-3-carboxamide 10,10-dioxide, m.p. 307°-310° C. TLC (CHCl3 /MeOH/9/1) Rf =0.45.

Provenance & Evidence