反应详情

To 2.2 ml of concentrated hydrochloric acid and 2.0 ml of pyridine which were heated to 220° for 20 minutes, 2.00 g of 2- carboxy-7-methoxy-10,11-dihydro-5-oxo-5H-dibenzo[a,d]cycloheptene was added. The mixture was heated to 210°-215° for 90 minutes, then cooled and diluted with water. The product was filtered off and recrystallized from aqueous ethanol to give 2-carboxy-7-hydroxy-10,11-dihydro-5-oxo-5H-dibenzo[a,d]cycloheptene, m.p. 256°-257°. Similarly, the 8-hydroxy and 9-hydroxy compounds of this invention are obtained from 2-carboxy-8-methoxy-10,11-dihydro-5-oxo-5H-dibenzo[a,d]cycloheptene and 2-carboxy-9-methoxy-10,11-dihydro-5-oxo-5H-dibenzo[a,d]cycloheptene, respectively.

1. temperatureThe mixture was heated to 210°-215° for 90 minutes
2. temperaturecooled
3. filtrationThe product was filtered off
4. customrecrystallized from aqueous ethanol