Premium
Synthesis of Some amino‐4,5‐dihydropyrazolo[3,4‐ a ]acridines as potential cholinesterase inhibitors
Author(s) -
Shutske Gregory M.,
Tomer John D.
Publication year - 1993
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.5570300104
Subject(s) - chemistry , acridine , hydrazine (antidepressant) , dimethylformamide , acridine derivatives , ring (chemistry) , ketone , stereochemistry , cholinesterase , medicinal chemistry , organic chemistry , biochemistry , medicine , solvent
A synthesis of the 4,5‐dihydro derivatives of the previously known pyrazolo[3,4‐ a ]acridine ring system is described. The reaction of a 3,4‐dihydroacridin‐1(2 H )‐one with N,N ‐dimethylformamide dimethyl acetal gave a reactive enamino ketone, which yielded the desired heterocycle upon reaction with hydrazine. Using this chemistry, 11‐amino‐4,5‐dihydro‐2 H ‐pyrazolo[3,4‐ a )acridine ( 3 ) and a number of its 2‐substituted derivatives 4a‐k were synthesized and evaluated as acetylcholinesterase inhibitors, based on their relationship to 1,2,3,4‐tetrahydro‐9‐acridinamine (THA). 1‐Amino‐4,5‐dihydro‐1 H ‐pyrazolo[3,4‐ a ]acridine ( 11a ) and 2‐amino‐4,5‐dihydro‐1 H ‐pyrazolo[3,4‐ a ]acridine ( 11b ) were also synthesized and investigated as potential cholinesterase inhibitors.