反应详情

5-(3-Dimethylaminoprop-2-en-1-oyl)-1,2-dimethylimidazole (Method 15; 2.8 g, 14.5 mmol) and guanidine hydrochloride (3.5 g, 36.3 mmol) were suspended in 1-butanol (30 ml). Sodium methoxide (3.1 g, 58 mmol) was added in one portion and the mixture heated under reflux, under an atmosphere of nitrogen, for 18 hours. The reaction mixture was allowed to cool to ambient temperature and was pre-absorbed on to silica gel and purified by column chromatography on silica gel eluting with DCM/2% methanolic ammonia (100:0 increasing in polarity to 95:5) to give the title compound (2.3 g, 84%). NMR 2.16 (s, 3H), 3.93 (s, 3H) 6.52 (s, 2H), 6.80 (d, 1H), 7.47 (s, 1H), 8.17 (d, 1H); m/z 190.

1. temperaturethe mixture heated
2. temperatureunder reflux, under an atmosphere of nitrogen, for 18 hours
3. customwas pre-absorbed on to silica gel
4. custompurified by column chromatography on silica gel eluting with DCM/2% methanolic ammonia (100:0 increasing in polarity to 95:5)