Click chemistry: Studies on the synthesis of novel fluorous tagged triazol-4-yl substituted quinazoline derivatives and their biological evaluation – Theoretical and experimental validation
The formation of N- and O-propargylated quinazoline derivatives 2, 3 from quinazol-4-ones 1 was theoretically predicted by optimizations at B3LYP/6-31G* level, analysed kinetically and thermodynamically. Theoretical predictions are validated by experiment to observe the trends and found deviation. Thus, compound I was propargylated in basic media to obtain compound 2 and 3 in definite proportions. Each compound was further subjected to [3 + 2] cycloaddition using perfluoroalkyl azides through Click reaction under Sharpless conditions, and obtained a series of novel perfluoroalkyl-1H,1,2,3-triazol-4-yl substituted quinazolines 4, 5, and 6. All the compounds were screened for antimicrobial activity and identified potential compounds. (C) 2009 Published by Elsevier Masson SAS.
Copper-Catalyzed Domino Synthesis of Quinazolin-4(3H)-ones from (Hetero)arylmethyl Halides, Bromoacetate, and Cinnamyl Bromide
Alkyl halides, including heteroarylmethyl and arylmethyl halides, bromoacetate, and cinnamyl bromide, are readily prepared via halogenation from basic raw materials, even using green processes. It is essential to replace their downstream products with them to prepare medicinally important heterocycles quinazolin-4(3H)-ones. Copper(I) bromide catalyzed domino reaction of alkyl halides and anthranilamides under air affords 2-substituted quinazolin-4(3H)-ones in good to excellent yields and with wide functional group tolerance. A mechanism for a copper(I) bromide involved organometal-catalyzed reaction via a four-step domino reaction is proposed.