N-Iodosuccinimide → 7-Chloro-2-(2-chlorophenyl)-3-iodo-5-methylpyrazolo[1,5-a]pyrimidine

Participants

Reaction Steps

To a solution of 7-chloro-2-(2-chlorophenyl)-5-methylpyrazolo[1,5-a]pyrimidine (I-1A-3g; 370 mg, 1.33 mmol) in 5:1 methylene chloride/chloroform (9 ml) cooled in an ice bath was added N-iodosuccinimide (449 mg, 2.0 mmol), portionwise, to give a heterogeneous mixture. After 1.5 hours, the ice bath was removed and the reaction was stirred an additional 2.5 hours to give a homogenous, pink solution. The reaction was extracted from aqueous NaHCO3 with methylene chloride. The combined extracts were washed with saturated aqueous Na2S2O4 and brine, dried (MgSO4), and then concentrated, in vacuo, to afford product I-1A-3h as a tan solid (535 mg, quantitative): +ESI MS (M+1) 403.9; 1H NMR (400 MHz, CD2Cl2) δ 7.57–7.40 (m, 4H), 6.99 (s, 1H), 2.66 (s, 3H).

Provenance & Evidence