196085-87-7Relevant articles and documents
Unexpected copper-catalyzed cascade synthesis of quinazoline derivatives
Chen, Zhongyan,Chen, Jiuxi,Liu, Miaochang,Ding, Jinchang,Gao, Wenxia,Huang, Xiaobo,Wu, Huayue
, p. 11342 - 11348 (2013/12/04)
The first example of a copper-catalyzed cascade reaction of (2-aminophenyl)methanols with aldehydes using the combination of cerium nitrate hexahydrate and ammonium chloride has been developed, leading to a wide range of 2-substituted quinazolines in moderate to excellent yields. The efficiency of this transformation was demonstrated by compatibility with a wide range of functional groups. Thus, the method represents a convenient and practical strategy for synthesis of 2-substituted quinazoline derivatives.
Synthesis of 3h-quinazolin-4-ones and 4h-3,1-benzoxazin-4-ones via benzylic oxidation and oxidative dehydrogenation using potassium iodide-tert-butyl hydroperoxide
Kumar, R. Arun,Maheswari, C. Uma,Ghantasala, Satheesh,Jyothi,Reddy, K. Rajender
supporting information; experimental part, p. 401 - 410 (2011/04/18)
A simple and elegant method for benzylic activation was demonstrated employing the potassium iodide/tert-butyl hydrogen peroxide catalytic system. This methodology was further extended for the synthesis of biologically important heterocycles namely, 3H-quinazolin-4-ones and 4H-3,1-benzoxazin-4-ones including mecloqualone and etaqualone which are important quinazolinone-based drugs used for the treatment of insomnia in good yields.
Kinetics and mechanism of the addition of water and ring-opening of 2-methyl- and 2-aryl-4H-3,1-benzoxazines to 2-aminobenzyl esters in the acidic pH range; change in rate-limiting step with buffer concentration and evidence for a tetrahedral carbonyl addition intermediate
Dixon, Wendy J.,Hibbert, Frank,Mills, Judith F.
, p. 1503 - 1509 (2007/10/03)
The observed rate coefficients for the reaction of 2-methyl-, 2-phenyl- and 2-(4-nitrophenyl)-4H-3,1-benzoxazines to give the corresponding 2-aminobenzyl esters increase as the pH is lowered and reach a constant plateau value at pH 2-4 depending on the substituent. The plateau region corresponds to complete conversion of the benzoxazine to the protonated benzoxazine (SH+) which is the reactive species. Values of pKSH+ calculated by fitting the appropriate rate expression to the rate-pH profile and the pKSH+ values measured spectrophotometrically before significant reaction to the ester has taken place are in good agreement. For each benzoxazine the observed rate coefficients show a rectilinear dependence on buffer concentration. A mechanism is proposed involving addition of water to the protonated benzoxazine to give a cyclic tetrahedral carbonyl addition intermediate. At low buffer concentrations, buffer catalysed collapse of the intermediate to product is rate-limiting and the reaction is first order in buffer. At high buffer concentrations, collapse of the intermediate to product is rapid and addition of water to the protonated benzoxazine to give the intermediate is rate-limiting.
