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The regiospecific synthesis of N ‐substituted pyrazoles. I. 1‐ and 2‐substituted indeno[1,2‐c]pyrazol‐4(1 H )‐ones
Author(s) -
Lemke Thomas L.,
Sawhney Kailash N.
Publication year - 1982
Publication title -
journal of heterocyclic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.321
H-Index - 59
eISSN - 1943-5193
pISSN - 0022-152X
DOI - 10.1002/jhet.5570190616
Subject(s) - chemistry , amine gas treating , chemical shift , medicinal chemistry , stereochemistry , organic chemistry
The reaction of the enaminoketones ( 2 or 5 ) of 2‐acyl‐1,3‐indandiones with unsymmetrical hydrazines results in the regiospecific synthesis of 1,3‐ or 2,3‐disubstituted indeno[1,2‐ c ]pyrazol‐4(1 H )‐ones ( 4 or 7 ). The synthesis of the enaminoketones ( 2 or 5 ) is accomplished by way of amine addition to the 2‐acyl‐1,3‐indandiones 8a‐c or by reduction of the indenoisoxazole 9 . The structural assignment of the isomeric indenopyrazoles 4 and 7 is based upon 1 H‐nmr chemical shifts.