Thionyl Chloride → 3-Methylthio-8-oxo-6-(2-allyloxyphenyl)-7,8-dihydropyrimido[4,5-e][1,2,4]triazine

Participants

Reaction Steps

A cooled (5° C.) solution of 3-methylthio-5-chloro-6-carboethoxy-1,2,4-triazine (prepared by heating 3-methylthio-5-oxo-6-carboethoxy-4,5-dihydro-1,2,4-triazine, 1.5 g, with thionyl chloride, 30 ml, under reflux for two hours and thereafter removing thionyl chloride) in acetonitrile (30 ml) was added to a cooled stirred mixture of 2-allyloxybenzamidine hydrochloride (2.23 g) and triethylamine (1.06 g) in acetonitrile (50 ml). The mixture was stirred with cooling (0°-5° C.) for 15 minutes, then more triethylamine (0.71 g) was added and the reaction mixture was stirred at ambient temperature for two hours and left standing overnight. A yellow precipitate was collected, washed with water and recrystallised from acetonitrile and then from acetonitrile/ethanol (50%) to afford the title compound, 0.35 g, m.p. 238°-239° C.

Provenance & Evidence