4,4-Dimethoxy-2-butanone → 2-Benzylthio-7-methyl-1,2,4-triazolo[1,5-a]pyrimidine

Participants

Reaction Conditions

Reaction Steps

A solution of 50 g (0.24 mol) of 3-amino-5-benzylthio-1,2,4-triazole in 500 ml of glacial acetic acid was added dropwise over 3-4 hours to a solution of 34.0 g (0.25 mol) of acetylacetaldehyde dimethyl acetal in 500 ml of glacial acetic acid heated at 100° C. After the addition was complete the reaction mixture was heated at reflux overnight, cooled to room temperature and poured into an ice-water mixture. The solid which separated was collected by filtration and recrystallized from ethanol to yield 27 g (41%) of the desired product as a solid, m.p. 102°-104° C. IR and 1H NMR spectra were in agreement with the assigned structure.

Provenance & Evidence