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, at 25° C., to a suspension, which is stirred under pure nitrogen, of 100.1 g (1.1 moles) of sodium 1,2,4-triazolide in 300 ml of dry tetrahydrofuran. After refluxing the mixture for eight hours, the inorganic precipitate is filtered off and the filtrate is concentrated to half its volume. The mixture is seeded and left to stand overnight at +3° C. The precipitate is filtered off, washed with 30 ml of cold tetrahydrofuran (at +5° C.), 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