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Catalyst‐ and solvent‐free synthesis of 2‐fluoro‐ N ‐(3‐methylsulfanyl‐1 H ‐1,2,4‐triazol‐5‐yl)benzamide through a microwave‐assisted Fries rearrangement: X‐ray structural and theoretical studies
Author(s) -
Moreno-Fuquen Rodolfo,
Arango-Daraviña Kevin,
Becerra Diana,
Castillo Juan-Carlos,
Kennedy Alan R.,
Macías Mario A.
Publication year - 2019
Publication title -
acta crystallographica section c
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.304
H-Index - 17
ISSN - 2053-2296
DOI - 10.1107/s2053229619002572
Subject(s) - benzamide , chemistry , catalysis , fries rearrangement , regioselectivity , acylation , amide , density functional theory , intermolecular force , solvent , medicinal chemistry , stereochemistry , crystallography , molecule , computational chemistry , organic chemistry
An efficient approach for the regioselective synthesis of (5‐amino‐3‐methylsulfanyl‐1 H ‐1,2,4‐triazol‐1‐yl)(2‐fluorophenyl)methanone, C 10 H 9 FN 4 OS, (3), from the N ‐acylation of 3‐amino‐5‐methylsulfanyl‐1 H ‐1,2,4‐triazole, (1), with 2‐fluorobenzoyl chloride has been developed. Heterocyclic amide (3) was used successfully as a strategic intermediate for the preparation of 2‐fluoro‐ N ‐(3‐methylsulfanyl‐1 H ‐1,2,4‐triazol‐5‐yl)benzamide, C 10 H 9 FN 4 OS, (4), through a microwave‐assisted Fries rearrangement under catalyst‐ and solvent‐free conditions. Theoretical studies of the prototropy process of (1) and the Fries rearrangement of (3) to provide (4), involving the formation of an intimate ion pair as the key step, were carried out by density functional theory (DFT) calculations. The crystallographic analysis of the intermolecular interactions and the energy frameworks based on the effects of the different molecular conformations of (3) and (4) are described.