Light induced oxidation of 2,3-dihydroquinazolin-4(1H)-ones
摘要:
Light induced oxidation of various of 2-substituted 2,3-dihydroquinazolin-4(1H)-ones (DHQZs) results smoothly the formation of quinazolin-4(3H)-ones (QZs) product. The electronic nature of the substituent on the 2-position and also the nature of solvent affect the rate of reaction, which supports the proposed mechanism based on the electron-transfer induced photo-oxidation. Analysis of the computational results obtained at the DFT-B3LYP/6-31++G** level of theory supports the mechanism in which the first electron removal occurs preferably from the N1 atom of the heterocyclic ring. In contrast to the solution photochemistry, no changes have been observed by irradiation in the solid state. (C) 2013 Elsevier B.V. All rights reserved.
An efficientone-potsynthesis of 2,3-dihydroquinazoline-4(1H)-one derivatives 4a–l is described using SBA-Pr-SO3H as a heterogeneous acid catalyst. The present methodology resulted in various derivatives of 2,3-dihydroquinazoline-4(1H)-one in good yield via a three-component reaction of isatoic anhydride, aldehydes and ammonium acetate. SBA-Pr-SO3H played a significant role as an efficient mesoporous