Rearrangements of quinazolines

Thermally induced rearrangement of quinazoline derivative 8 affords ethyl A -[(6-methyl-l,3-dioxolo[4,5-g]quinazolin-8-yl)methyl]carbamate (9a) in 5 /o yield. Similarly, the thermal and photochemical rearrangement of ethyl A-(6-methyl-8-methylene-l,3-dioxolo[4,5-g]quinazolin-7-yl)-A-phenylcarbamate (7b) produces ethyl A -[(6-methyl-l,3-dioxolo[4,5-g]quinazolin-8-yl)-methyl]-Ai -phenylcarbamate (9b) in 45% yield. Thermal rearrangement of 8, therefore, probably involves the tautomeric methylene base 7a (R = H) as an intermediate. 

An intimate mixture of anthranilonitrile and phenyl isothiocyanate heated to 100° whereupon a vigorous exothermic reaction takes place during a few min., and the product isolated after 12 hrs. at 100° 2-thio-4-anilino-l,2-dihydro-quinazoline. Y 97%. F. e., isolation of intermediates, and rearrangement of quinazolines, s. E. C. Taylor and R. V. Ravindranathan, J. Org. Chem. 27, 2622 (1962). 

Another example includes rearrangement of quinazoline derivative 1257 into benzodiazepine 1258, described in a patent (Scheme 290) [789],... 

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