Diethyl Carbonate → HCID 135974540, compound

Participants

Reaction Steps

To an ethanolic solution of sodium ethoxide, generated by portionwise addition of sodium metal (4.2 g, 185 mmol) to stirred ethanol (250 ml), was added N-[5-(2-chlorophenyl)-2H-pyrazol-3-yl]-formamidine, acetate salt (I-3A-9b; 5.2 g, 18.5 mmol) in one portion. Diethylcarbonate (17.8 ml, 148 mmol) was added, dropwise, and the mixture was heated at reflux for 2 hours. After cooling to room temperature, the reaction was concentrated, in vacuo, and then extracted with ethyl acetate from water after adjusting to pH 7 with 3 M aqueous HCL. The combined organic layers were washed with water and then brine, dried (MgSO4), filtered, and then concentrated, in vacuo, to one-third volume at which time a precipitate began to form. After stirring overnight, the product was collected by vacuum filtration and then dried, in vacuo, to afford I-3A-9c as a solid (2.61 g, 57%). A second crop of the intermediate was collected from the filtrate after standing an additional 24 hours (600 mg, 19%): +ESI MS (M+1) 247.1; 1H NMR (400 MHz, CD3OD) δ 7.97 (s, 1H), 7.86-7.82 (m, 1H), 7.55-7.51 (m, 1H), 7.45-7.39 (m, 2H), 6.92 (s, 1H).

Provenance & Evidence