反应详情

温度

100 °C

To a mixture under nitrogen of 4.00 g (10.6 mmol) of tert-butyl 7-bromo-8-carbamoyl-6-chloro-3,4-dihydropyrrolo[1,2-a]pyrazine-2(1H)-carboxylate under N2 with the bromo derivative of pyrrolo[1,2-a]pyrazine, 1.77 g (11.6 mmol) of 4-methoxyphenylboronic acid and 10.3 g (31.7 mmol) of caesium carbonate in a mixture of 80 ml of tetrahydrofuran and 4 ml of water is added 0.863 g (1.06 mmol) of 1,1′-bis(diphenylphosphino)ferrocenedichloropalladium (II) (CAS 72287-26-4). The mixture is heated at 100° C. for 20 hours and, after cooling, the medium is then diluted with ethyl acetate and filtered through Celite. The filtrate is washed with water, the organic phase is dried over sodium sulfate and concentrated under reduced pressure, and the residue is chromatographed on a column of 40 g of silica gel, eluting with 5 to 100% ethyl acetate in dichloromethane, to give 3.35 g of tert-butyl 8-carbamoyl-6-chloro-7-(4-methoxyphenyl)-3,4-dihydropyrrolo[1,2-a]pyrazine-2(1H)-carboxylate after crystallization from ethyl acetate and drying.

1. temperatureafter cooling
2. filtrationfiltered through Celite
3. washThe filtrate is washed with water
4. dry with materialthe organic phase is dried over sodium sulfate
5. concentrationconcentrated under reduced pressure
6. customthe residue is chromatographed on a column of 40 g of silica gel
7. washeluting with 5 to 100% ethyl acetate in dichloromethane