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Reactivity of some 3‐substituted‐6,8‐dimethylchromones toward some nucleophilic reagents
Author(s) -
Badran AlShimaa,
ElGohary Nasser M.,
Ibrahim Magdy A.,
Hashiem Salsabeel H.
Publication year - 2020
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.3975
Subject(s) - chemistry , nucleophile , reactivity (psychology) , nitrile , reagent , aldehyde , decarboxylation , medicinal chemistry , cycloaddition , nucleophilic addition , organic chemistry , catalysis , medicine , alternative medicine , pathology
Abstract The reactivity of 3‐substituted‐6,8‐dimethylchromone derivatives 1 ‐ 5 was investigated toward selected nucleophilic reagents namely; 3‐amino‐1,2,4‐triazole, 2‐aminobenzimidazole, 7‐chloro‐4‐hydrazinoquinoline, and 5,6‐diphenyl‐3‐hydrazino‐1,2,4‐triazine. These nucleophiles were allowed to react with 6,8‐dimethylchromone‐3‐carboxaldehyde ( 1 ) through condensation with the aldehyde group with opening of γ‐pyrone ring giving compounds 6 , 7 , 10, and 11 . Reactions with 6,8‐dimethylchromone‐3‐carbonitrile ( 2 ), and 6,8‐dimethylchromone‐3‐carboxylic acid ( 3 ) occur via attack at position 2 in both compounds followed by cycloaddition onto the nitrile function (in case of carbonitrile 2 ) or decarboxylation and cyclocondensation with the carbonyl group (in case of carboxylic acid 3 ). The current nucleophilic reagents reacted with simple condensation products 4 and 5 , in boiling dioxane, through nucleophilic addition at the exocyclic vinyl bond followed by addition at the CN group giving 6,8‐dimethylchromone linked various heterocyclic systems 20 ‐ 27 .