Hydrochloric Acid → 877133-14-7

Participants

Reaction Conditions

Reaction Steps

Water (190 mL) was added to 5-(diethoxymethyl)-3-(difluoromethyl)-1-methyl-1H-1,2,4-triazole (47.6 g, 0.2024 mol, from Step 2), and the mixture was degassed. Then concentrated HCl (73 mL, 0.81 mol, 11.1 M) was added, and the mixture was stirred at 55-60° C. for 24 h. After this, the reaction mixture was evaporated, and the residue was repeatedly (8-10 times) evaporated with THF until the water and HCl were completely removed. The final residue was distilled under vacuum to give the crude title product (bp 46-50° C. at 0.04 mm Hg), containing, according to LC-MS data, 7% of a dimerization side-product. Further purification on a silica gel (ethyl acetate/hexane 1:3) yielded 18.37 g (56.3%) of 3-(difluoromethyl)-1-methyl-1H-1,2,4-triazole-5-carbaldehyde. Satisfactory C,H,N-analysis was obtained. 1H NMR (400 MHz, CDCl3): δ 4.25 (s, 3H), 6.74 (t, J=56 Hz, 1H), 10.01 (s, 1H). LC/MS (API-ES) calcd for C5H5F2N3O: 161.04, found (M+H+): 162.1; (M+18+H+): 180.1 m/z.

Provenance & Evidence