Hydrochloric Acid → Imidazo(1,2-a)pyrimidine-6-carboxylic acid

Participants

Reaction Steps

A mixture of 6-bromoimidazo[1,2-a]pyrimidine (1.17 g, 6 mmol), BINAP (18 mg, 0.06 mmol), PdCl2 (6 mg) in MeOH (30 mL) and triethylamine (1.8 mL) was heated to 80° C. under CO (50 psi) for 12 hours in DMF (97.5 mL). DMF-DMA (70.6 mL, 495.8 mmol) was added and the mixture heated to 130° C. for 12 hours. The mixture was filtered and concentrated to give methyl imidazo[1,2-a]pyrimidine-6-carboxylate (365 mg, 35%) as a yellow solid which was used in the next step without further purification. To a solution of methyl imidazo[1,2-a]pyrimidine-6-carboxylate (365 mg, 2.1 mmol) in methanol was added 1M aq. LiOH (9.0 mL) and the resulting mixture was stirred for 10 hours at room temperature. The pH was adjusted to 5-6 using aq. HCl and the whole mixture extracted with EtOAc (3×30 mL). The combined organic layers were dried over Na2SO4 and evaporated in vacuo to give the title compound as white solid in 39% yield, 133 mg

Provenance & Evidence