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Pyrazolo [1,5‐ a ]indole. 10. Mitteilung über metallogranische reaktionen und folgeprodukte
Author(s) -
Marxer Adrian,
Siegrist Max
Publication year - 1979
Publication title -
helvetica chimica acta
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.74
H-Index - 82
eISSN - 1522-2675
pISSN - 0018-019X
DOI - 10.1002/hlca.19790620608
Subject(s) - chemistry , indole test , potassium hydroxide , ring (chemistry) , ethanol , aryl , medicinal chemistry , sodium hydroxide , tricyclic , sodium , potassium , stereochemistry , organic chemistry , alkyl
Pyrazolo[1,5‐ a ]indoles Treatment of 1‐(2‐heteroaroyl or aroyl‐phenyl)‐pyrazoles ( 3 ) with potassium hydroxide in 95% ethanol or with sodium ethanolate in ethanol produces a novel ring closure to new 4‐hydroxy‐4‐(4‐heteroaryl or aryl)‐4 H ‐pyrazolo [1,5‐ a ]indoles 5 and 6 (Table 1) . A 2, 3, or 4‐pyridyl at position 4 is easily reduced yielding the 4‐(2, 3, or 4‐piperidyl)‐derivatives 7 and 8 (Table 2) . Water is split off from these piperidyl‐derivatives 7 or 8 to give the piperidylidene derivatives 9 or 10 (Table 3) which may be considered as heterocyclic analogues to known tricyclic psychopharmaceuticals with antidepressant or neuroleptic activities.