Hydrochloric Acid → 3-Methylthio-8-oxo-6-(2-methoxyphenyl)-7,8-dihydropyrimido[4,5-e][1,2,4]triazine

Participants

Reaction Conditions

Reaction Steps

A cooled (0° C.) solution of 2-methoxybenzamidine (from 1.97 g of the hydrochloride) in acetonitrile (17 ml) was added to a cooled solution of 3-methylthio-5-chloro-6-carboethoxy-1,2,4-triazine (prepared from 3-methylthio-5-oxo-6-carboethoxy-4,5-dihydro-1,2,4-triazine, 1.08 g, and thionyl chloride, 20 ml) in acetonitrile (17 ml). Triethylamine (0.51 g) was added and the reaction mixture was stirred with cooling (0° C.) for one hour and then at ambient temperature for 17 hours to afford a yellow solid which was washed with acetonitrile and ether to afford the crude title compound (1.39 g). A sample (0.35 g) of this was washed twice with boiling methanol to afford the title compound, 0.25 g, m.p. 267.5°-268.5° C. The remaining material (1.04 g) was similarly treated with boiling methanol to afford the title compound, 0.91 g, m.p. 266°-268° C.

Provenance & Evidence