Cesium carbonate → (1-Aminoimidazo[1,5-a]pyridin-3-yl)(3-methoxy-4-nitrophenyl)methanone

Participants

Reaction Steps

8.67 g (26.61 mmol) of cesium carbonate and then 4.5 ml (26.82 mmol) of benzophenone imine are added, under a nitrogen atmosphere, to 5 g (13.29 mmol) of (1-bromoimidazo[1,5-a]pyridin-3-yl)(3-methoxy-4-nitrophenyl)methanone obtained in example 20 in 66 ml of N,N-dimethylformamide. After stirring for 30 minutes, 1.66 g (2.67 mmol) of 2,2′-bis(diphenylphosphino)-1,1′-binaphthalene and then 1.22 g (1.33 mmol) of tris(dibenzylideneacetone)dipalladium(0) are added. The reaction medium is heated for 3 hours and then concentrated under reduced pressure. The residue is taken up in a mixture of dichloromethane and water. The organic phase is separated by settling, dried over sodium sulfate and concentrated under reduced pressure. The residue is taken up in 250 ml of tetrahydrofuran and 135 ml of a 2N aqueous hydrochloric acid solution are added. After stirring at ambient temperature for one hour, the reaction medium is concentrated under reduced pressure. The solid residue obtained is taken up in acetone, filtered off, washed with acetone and then with ethyl ether and dried. 3.43 g of a brown solid are collected. Melting point: 214° C.; 1H NMR (d6-DMSO): 4.02 (3H, s), 7.29-7.36 (2H, m), 7.96-8.04 (2H, m), 8.11 (1H, d), 8.16 (1H, s), 9.78 (1H, d)

Provenance & Evidence