Base dependent purported synthesis of congested 2-aminobenzylamines and tetrahydro-2-oxoquinazolines from 2-pyranones
摘要:
An expeditious and concise synthesis of highly congested 2-amino-3-aminomethyl-5-methylsulfanyl/-sec-aminobiphenyl-4-carbonitrile 4 and 1-tert-butoxycarbonyl-6-sec-amino-8-aryl-5-cyano-2-oxo-1,2,3, 4-tetrahydroquinazoline 5 has been delineated through base catalyzed ring transformation of 6-aryl-4-methylsulfanyl/-sec-amino-2H-pyran-2-one-3-carbonitrile 1 with 1,3-bis(tert-butoxycarbonylamino)-2-propanone 2, followed by TFA catalyzed hydrolysis of the intermediate [3-tert-butoxycarbonyl-aminomethyl-4-cyano-5-methylsulfanyl/-sec-aminobiphenyl-2-yl]carbamic acid tert-butyl ester 3 in moderate yield. The mechanism of formation of 5 has been established through isolation and transformation of the intermediate 3 to the 1-tert-butoxycarbonyl-6-sec-amino-8-aryl-5-cyano-2-oxo-1,2,3,4-tetrahydroquinazoline. (C) 2009 Elsevier Ltd. All rights reserved.
Base dependent purported synthesis of congested 2-aminobenzylamines and tetrahydro-2-oxoquinazolines from 2-pyranones
作者:Farhanullah、Farhana Samrin、Vishnu Ji Ram
DOI:10.1016/j.tet.2008.12.041
日期:2009.2
An expeditious and concise synthesis of highly congested 2-amino-3-aminomethyl-5-methylsulfanyl/-sec-aminobiphenyl-4-carbonitrile 4 and 1-tert-butoxycarbonyl-6-sec-amino-8-aryl-5-cyano-2-oxo-1,2,3, 4-tetrahydroquinazoline 5 has been delineated through base catalyzed ring transformation of 6-aryl-4-methylsulfanyl/-sec-amino-2H-pyran-2-one-3-carbonitrile 1 with 1,3-bis(tert-butoxycarbonylamino)-2-propanone 2, followed by TFA catalyzed hydrolysis of the intermediate [3-tert-butoxycarbonyl-aminomethyl-4-cyano-5-methylsulfanyl/-sec-aminobiphenyl-2-yl]carbamic acid tert-butyl ester 3 in moderate yield. The mechanism of formation of 5 has been established through isolation and transformation of the intermediate 3 to the 1-tert-butoxycarbonyl-6-sec-amino-8-aryl-5-cyano-2-oxo-1,2,3,4-tetrahydroquinazoline. (C) 2009 Elsevier Ltd. All rights reserved.