13610-55-4Relevant articles and documents
Synthesis of 3-alkylbenzoxazolones from N-alkyl-N-arylhydroxylamines by contiguous O-trichloroacetylation, trichloroacetoxy ortho-shift, and cyclization sequence
Ram, Ram N.,Soni, Vineet Kumar
, p. 11935 - 11947 (2014/01/06)
Benzoxazolone pharmacophore is present in clinical pharmaceuticals, drug candidates, and many compounds having a wide spectrum of biological activities. The methods available for the synthesis of benzoxazolones have limited diversity due to problems in accessibility and air-sensitivity of diversely substituted o-aminophenols from which they are generally prepared by cyclocarbonylation with phosgene or its equivalents. The present paper describes a mild method for the synthesis of 3-alkylbenzoxazolones from easily accessible and air-stable nitroarenes. Nitroarenes were converted to N-alkyl-N-arylhydroxylamines in two steps involving partial reduction to arylhydroxylamines followed by selective N-alkylation. Treatment of N-alkyl-N-arylhydroxylamines with trichloroacetyl chloride and triethylamine afforded 3-alkylbenzoxazolones generally in good yields through an uninterrupted three-step sequence involving O-trichloroacetylation, N→Cortho trichloroacetoxy shift, and cyclization in a single pot at ambient temperatures. The present method is mild, wide in scope, economical, and regioselective. Many sensitive groups like alkyl and aryl esters, amide, cyano, and the carbon-carbon double bond survive the reaction.
Derivatives of 2-Oxo-3(2H)-benzothiazolineacetonitrile and Related Compounds. II. Synthesis of 2-Oxo-alkyl Esters of 3(2H)-Benzothiazolineacetimidic Acids and Related Products
D'Amico, John J.,Bollinger, Frederic G.
, p. 1487 - 1496 (2007/10/02)
The reaction of the appropriate 2-benzothiazolinone or 2-benzoxazolinone under basic conditions with (1) 2-chloropropionitrile, (2) acrylonitrile, (3) 4-chlorobutyronitrile or (4) chloroacetonitrile afforded the nitriles 1-8.The reaction of various nitriles with alcoholic-hydrogen chloroide solutions at low temperatures afforded the hydrogen chloride salts of the imino-ester which upon neutralization with potassium carbonate yielded the titled compounds.
