反应详情

A reaction flask equipped with a mechanical stirrer and a reflux condenser is charged with EtOH (900 mL), Ethyl-3-(ethanimidoylamino)-5-methyl-1H-pyrrole-2-carboxylate hydrochloride from example A5 (82.79 g; 0.34 mol) and 6M NaOH (226 mL; 1.36 mol). The well-stirred reaction mixture is heated to gentle reflux for 4 hours and is cooled to ambient temperature. The resulting solution is diluted with water (1000 mL) and the pH is adjusted to 6.5 by carefully addition of 2M citric acid. The precipitate is collected by suction filtration, washed with several portions of water and dried in vacuum at 50° C. to yield the title compound as off-white solid.

1. customA reaction flask equipped with a mechanical stirrer and a reflux condenser
2. customThe well-stirred reaction mixture
3. temperatureis heated
4. temperatureto gentle reflux for 4 hours
5. filtrationThe precipitate is collected by suction filtration
6. washwashed with several portions of water
7. customdried in vacuum at 50° C.