Quinazolines XI. Condensation of deoxyvasicinone with aldehydes

Summary In the reaction of deoxyvasicinone with aldehydes, depending on the nature of the substituents of aromatic and heterocyclic aldehydes, and also on the reaction conditions, 9-benzylidene or 9--hydroxybenzyl derivatives of deoxyvasicinone are obtained.Institute of the Chemistry of Plant Substances, Academy of Science of the Uzbek SSR, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 4, pp. 552–556, July–August, 1977.     

Mass spectra of 2,3-polymethylene-3,4-dihydroquinazolin-4-ones with substituents at C9

Summary The main fragments in the mass spectra of the 2,3-polymethylene-3,4-dihydroquinazolin-4-one with six- and seven-membered alicyclic rings are formed by the decomposition of ring C through the stage of the cleavage of the C₉-C₁₀ bond, while the compound with a five-membered ring ejects a hydrogen atom.A hydroxy group at C₉ initiates the appearance of fragments due to the initial cleavage of the C₂-C₉ bond. In the spectra of the halogen and acetoxy derivatives the fragmentation of the alicyclic ring is suppressed and the main fragmentation pathway is the splitting out of the substituent. The hypothesis of the protonation of the N₁ nitrogen atom has been adopted to explain the stability of a number of the ions.Institute of the Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSR, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 2, pp. 180–187, March–April, 1979.