Phosphorus oxychloride → HCID 86661440, compound

Participants

Reaction Steps

A mixture of 5-oxo-4,5-dihydropyrazolo[1,5-c]pyrimidine-3-carboxylic acid (2.0 g, 10 mM, 1.0 equiv), 30 mL of phosphorus oxychloride (300 mM, 30 equiv) and N,N-diisopropylethylamine (8 mL, 40 mM, 4 equiv) was heated with stirring to reflux for 2 hours. The reaction mixture was cooled and concentrated under vacuum. The brown oil was taken up in dichloromethane and isopropylamine added (3 mL, 30 mM, 3 equiv). The reaction mixture was stirred 5 minutes then partitioned between ethyl acetate and water. The organic phase was washed with brine, dried over sodium sulfate and vacuum filtered through a pad of silica gel. The filtrate was concentrated and cooled and the crystallized product collected by filtration to give 2.31 g (90%) of 5-chloro-N-isopropylpyrazolo[1,5-c]pyrimidine-3-carboxamide. LCMS (ESI) m+H=239.1 (mono chlorinated isotope pattern) 1H NMR (400 MHz, DMSO-d6) δ: 9.33 (d, 1H), 8.60 (s, 1H), 7.47 (d, 1H), 7.36 (d, 1H), 4.09 (m, 1H), 1.20 (d, 6H).

Provenance & Evidence