p-Toluenesulfonic acid → 6-piperazin-1-yl-3H-pyrimidin-4-one

Participants

Reaction Steps

To a solution of 4-(6-oxo-1,6-dihydro-pyrimidin-4-yl)-piperazine-1-carboxylic acid tert-butyl ester (13.5 g, 48.2 mmol) in dichloromethane (200 mL) was added MP-TsOH (available from Aldrich; 81.0 g). The reaction was shaken at room temperature for 4 days. The crude reaction mixture was filtered and the resin was washed with methanol (460 mL). The desired product was eluted from the resin with 2M ammonia in methanol (460 mL) to give 6-piperazin-1-yl-3H-pyrimidin-4-one (8.4 g, 90%). LCMS Purity=96% (Rt=0.22 in the solvent front). 1H NMR (d6-DMSO) δ 7.75 (s, 1H), 5.10 (s, 1H), 2.60-2.42 (m, 4H), 2.38-2.25 (m, 4H).

Provenance & Evidence