Acetic Acid → HCID 178476698, compound

Participants

Reaction Steps

To a vigorously stirred solution of saturated aqueous Na2CO3 (50 mL) and methylene chloride (50 ml) was added solid ethylformimidate hydrochloride salt (8.98 g, 82 mol). After stirring for several minutes the aqueous layer was separated and extracted with additional methylene chloride (3×50 ml). The combined organic layers were dried (MgSO4) and filtered. To the stirred solution was added 5-(2-chlorophenyl)-2H-pyrazol-3-ylamine (I-3A-9a; 5.27 g, 27 mmol) in methylene chloride (50 mL) and then glacial acetic acid (2.67 ml, 46.6 mmol), dropwise. A cloudy precipitate began to form as the acetic acid was added. After stirring overnight, the solids were collected by vacuum filtration, washed with methylene chloride, and then dried, in vacuo, to give intermediate I-3A-9b, contaminated with ˜25% of the corresponding dimer (MW=396; 2 pyrazoles+1 formamidine), as a solid (5.7 g, 75%): +APcI MS (M+1) 221.1; 1H NMR (400 MHz, CD3OD) δ 8.02 (s, 1H), 7.62-7.30 (m, 4H), 6.48 (s, 1H), 1.92 (s, 3H).

Provenance & Evidence