Sulfur → Fluproquazone

Participants

Reaction Steps

17.4 g 1-isopropyl-4-(4-fluorophenyl)-7-methyl-4a,5,6,8a-tetrahydro-2(1H)-quinazolinone are dissolved under heating in 50 ml decaline and treated portionwise at 140° with 4 g powdered sulphur. On completion of the addition stirring is continued for 1 hour at 160°. The mixture is diluted with toluene and extracted several times with 15% hydrochloric acid. The acidic phase is treated with methylene chloride and neutralized under ice cooling with sodium hydroxide solution. The water phase is extracted with methylene chloride and the combined methylene chloride extracts concentrated in vacuo. The concentrate is chromatographed on silica gel using dichloromethane and methanol as eluant. After recrystallisation from toluene the title compound is obtained, m.p. 174°-176°.

Provenance & Evidence