2-Bromo-1-(5-methyl-1,3-dioxan-5-yl)ethan-1-one → 1-(5-Methyl-1,3-dioxan-5-yl)-2-(1,2,4-triazol-1-yl)-ethan-1-one

Participants

Reaction Steps

A solution of 223 g (1 mole) of 1-(5-methyl-1,3-dioxan-5-yl)-2-bromoethan-1-one in 200 ml of tetrahydrofuran is added dropwise in the course of 2 hours to a suspension, stirred under pure nitrogen, of 100 g (1.1 moles) of sodium 1,2,4-triazolide in 300 ml of dry tetrahydrofuran, at 25° C. The mixture is refluxed for 8 hours, the inorganic precipitate is then filtered off, and the filtrate is concentrated to half its volume. It is then seeded and left to stand overnight at +3° C. The precipitate is filtered off, washed with 30 ml of cold (+5° C.) tetrahydrofuran, then with 80 ml of ether and thereafter with 100 ml of n-pentane, and dried. 184 g (87.2%) of 1-(5-methyl-1,3-dioxan-5-yl)-2-(1,2,4-triazol-1-yl)-ethan-1-one are obtained as white crystals of melting point 95°-97° C.

Provenance & Evidence