Triethylamine → 4-Chloro-1-ethyl-1,5,6,11-tetrahydrobenzo[5,6]cyclohepta[1,2-b]pyrazolo[4,3-e]pyridin-11-ol

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Reaction Steps

20.2 g. of 4-chloro-1-ethyl-5,6-dihydrobenzo[5,6]cyclohepta[1,2-b]pyrazolo[4,3-e]pyridin-11(1H)-one (0.065 mol.) and 13 g. of triethylamine (0.13 mol.), dissolved in 400 ml. of ethyl acetate and 75 ml. of absolute ethanol, are catalytically hydrogenated in the presence of 2 g. of palladium on charcoal (10%) at room temperature. In about 6 hours, the theoretical amount of hydrogen is absorbed. The catalyst is then filtered off, the filtrate evaporated in vacuo and the residue extracted with 200 ml. of ether. The ethereal extract is washed with water, dried with Na2SO4 and the ether removed. The resulting material is recrystallized from petroleum ether (60°-70°) to yield 12.7 g. (62.5%) of 4-chloro-1-ethyl-1,5,6,11-tetrahydro[5,6]cyclohepta[1,2-b]pyrazolo[4,3-e]pyridin-11-ol; m.p. 128°-130°.

Provenance & Evidence