Dimethyl methylmalonate → 7-hydroxy-6-methyl-2-phenylpyrazolo[1,5-a]pyrimidin-5(4H)-one

Participants

Reaction Conditions

Reaction Steps

To a solution of dimethyl methylmalonate (1.30 mL, 9.80 mmol) and 5-amino-3-phenylpyrazole (1.50 g, 9.42 mmol) in methanol (11 mL) is added 25% sodium methoxide in methanol (6.04 mL, 26.4 mmol). The reaction mixture is heated at 75° C. for 48 hr. The precipitate was collected in a Buchner funnel and washed with dichloromethane to provide 7-hydroxy-6-methyl-2-phenylpyrazolo[1,5-a]pyrimidin-5(4H)-one (2.87 g, yield 95%). LCMS: (AA) M+1 242; 1H NMR (400 MHz, DMSO) δ 10.39 (s, 1H), 7.92-7.86 (m, 2H), 7.41-7.33 (m, 2H), 7.32-7.26 (m, 1H), 5.92 (s, 1H), 1.75 (s, 3H).

Provenance & Evidence