Premium
Synthesis of 5,6‐dihydro‐2‐trifluoromethyl‐1,4‐dioxin‐3‐carboxanilides through polymer‐bound activated ester: Construction of dihydro‐1,4‐dioxin
Author(s) -
Mah Heduck,
Chang Kee Hyuk,
Nam Kee Dal,
Hahn HohGyu,
Bae Su Yeoul
Publication year - 2000
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.5570370452
Subject(s) - chemistry , trifluoromethyl , aniline , acetonitrile , ether , medicinal chemistry , nucleophilic substitution , chlorine , nucleophile , organic chemistry , polymer chemistry , catalysis , alkyl
Abstract A new construction of dihydro‐1,4‐dioxin and a synthesis of 5,6‐dihydro‐2‐trifluoromethyl‐1,4‐dioxin‐3‐carboxanilides 22 through polymer‐bound activated ester are described. An intermediate β‐hydroxy ether 18 was prepared from the substitution reaction of α‐thio‐α‐chloro compound 8 with ethylene glycol followed by treatment with Raney Ni. Replacement of hydroxy by chlorine and then dehydrochlorination afforded trifluoromethyl dihydro‐1,4‐dioxin ester 15. The polymer‐bound trifluoromethyl dihydro‐1,4‐dioxin‐3‐carboxylic acid, 4‐hydroxy‐3‐nitrobenzophenone ester ( 21 ) was prepared through the reaction of polystyrene‐bound 4‐hydroxy‐3‐nitrobenzophenone ( 19 ) with the trifluoromethyl dihydro‐1,4‐dioxin‐3‐carbonyl chloride ( 20 ). Refluxing of 21 with substituted aniline in acetonitrile gave the corresponding carboxanilide 22. The reaction rate depended on the nucleophilicity of nitrogen of the aniline.