Premium
PEG‐400 Mediated an Efficient Green Synthesis of Isoxazolyl Indole‐3‐Carboxylic Acid Esters via Nentizescu Condensation Reaction and Their Anti‐Inflammatory and Analgesic Activity
Author(s) -
Dharavath Nagaraju,
Eligeti Rajanarendar,
Reddy Y N,
Pittala Praveen Kumar,
Modugu Nagi Reddy
Publication year - 2017
Publication title -
chemistryselect
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.437
H-Index - 34
ISSN - 2365-6549
DOI - 10.1002/slct.201700640
Subject(s) - chemistry , polyethylene glycol , peg ratio , indole test , condensation reaction , carboxylic acid , proton nmr , carboxylate , organic chemistry , analgesic , catalysis , pharmacology , medicine , finance , economics
Polyethylene glycol‐400 (PEG‐400) has been discovered as an efficient and eco‐friendly reaction medium for the synthesis of new isoxazolyl indole‐3‐carboxylic acid esters 11 from 4‐amino‐3‐methyl‐5‐styrylisoxazoles 7 . Compounds 7 on treatment with β‐keto ester 8 afforded the corresponding isoxazolylamino‐2‐butenoates 9 at ambient temperature in PEG‐400. The Nentizescu condensation of compounds 9 with 1,4‐benzoquinone 10 to give the title compounds isoxazolyl indole‐3‐craboxylic acid esters 11 under PEG‐400. Structures of compounds 9 and 11 were established on the basis of IR, 1 H NMR, 13 C NMR and HRMS analysis. All the final compounds 11 a–s were evaluated for their anti‐inflammatory and analgesic activities. Among the compounds tested, the compounds 11 b , 11 g , 11 n , 11 o , 11 p and 11 s exhibited significant anti‐inflammatory and potent analgesic activities as that of standard drugs. The advantages of this protocol are: operational simplicity, environmental safety, broad substrate scope, excellent functional group tolerance, and good yields. The PEG‐400 can be recovered and reused.