反应详情

A mixture of 4.0 grams of 2-anilino-3-hydroxy-4-(phenylimino)-2-cyclobuten-1-one and 3.9 grams of 1-isopropylpiperazine is heated at 200°-206° C. in an atmosphere of dry nitrogen for 30 minutes. The mixture is cooled and the resulting solid is comminuted, washed with anhydrous ethyl ether, dried and then recrystallized from water to give 1-[2-hydroxy-3-(4-isopropyl-1-piperazinyl)-4-oxo-2-cyclobuten-1-ylidene]-4-isopropyl-piperazinium hydroxide inner salt melting at about 194.5°-196.5° C.

1. temperatureis heated at 200°-206° C. in an atmosphere of dry nitrogen for 30 minutes
2. temperatureThe mixture is cooled
3. customthe resulting solid is comminuted
4. washwashed with anhydrous ethyl ether
5. customdried
6. customrecrystallized from water