Dichloromethane → 5-Chloro-2-methyl-4-(o-tolyl)-2,4-dihydro[1,2,4]triazol-3-one

Participants

Reaction Steps

To a solution of 11.1 g of the title compound of Step A dissolved in 600 mL of methylene chloride under nitrogen was added 17.1 g of triphosgene. The solution was heated at reflux overnight, cooled, and then concentrated under reduced pressure. The resulting residue was dissolved in ethyl acetate, washed with water and then washed with saturated aqueous NaCl. The organic phase was dried (MgSO4), filtered, and concentrated under reduced pressure. The residue was purified by flash chromatography (30-50% ethyl acetate/hexanes as eluent) to afford 8.25 g (64% yield) of the title compound of Step B. 1H NMR (CDCl3): δ 7.42-7.30 (m,3H), 7.17 (d,1H), 3.54 (s,3H), 2.22 (s,3H).

Provenance & Evidence