Phosphorus oxychloride → 7-Chloro-3-(4-chlorophenyl)-2-(2-chlorophenyl)-6-methylpyrazolo[1,5-a]pyrimidine

Participants

Reaction Conditions

Reaction Steps

To a slurry of 3-(4-chlorophenyl)-2-(2-chlorophenyl)-6-methylpyrazolo[1,5-a]pyrimidin-7-ol (I-3A-1c; 119 mg, 0.321 mmol) and diisopropylethylamine (0.084 ml, 0.48 mmol) in toluene (2.2 ml) at room temperature was added POCl3 (0.15 ml, 1.61 mmol), dropwise. The mixture was heated at 100° C. for 22 hours, cooled to room temperature, then slowly added to a stirred mixture of ice, saturated aqueous sodium bicarbonate and ethyl acetate. The aqueous layer was separated and extracted with additional ethyl acetate. The combined organic layers were washed with brine, dried (MgSO4), and then concentrated, in vacuo, to afford the crude product (120 mg). Purification on a Biotage™ Flash 12M column using 0–8% ethyl acetate in hexanes as eluant afforded I-3A-1d (102 mg, 82%) as a yellow solid: +ESI MS (M+1) 388.1; 1H NMR (400 MHz, CD2Cl2) δ 8.44 (s, 1H), 7.55–7.37 (m, 6H), 7.27 (d, J=8.7 Hz, 2H), 2.51 (s, 3H).

Provenance & Evidence