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

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Reaction Steps

To a solution of 11.1 g 2,2-dimethyl-N-(2-methylphenyl) hydrazine carboxamide dissolved in 600 mL methylene chloride under N2 was added 17.1 g triphosgene. The solution was heated at reflux overnight, cooled, then concentrated under reduced pressure. The resulting residue was dissolved in ethyl acetate and washed with water, then 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%) 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