679404-19-4Relevant academic research and scientific papers
Studies on quinazolines, Part IV: Fused mesoionic heterocycles from 3-amino-2-aryl-4(3H)-quinazolinethiones
Wasfy
, p. 581 - 586 (2007/10/03)
The 3-amino-4(3H)-quinazolinethiones 2a-c react with phenyl isothiocyanate in DMF, giving N,N-disubstituted thioureas 3a-c. When 2a-c are treated with phenyl isothiocyanate in dry acetonitrile in the presence of triethylamine, the mesoionic compounds 4a-c are isolated. The methiodide 5a reacts with carbon nucleophiles such as malononitrile and/or ethyl cyanoacetate in the presence of triethylamine to give the corresponding 1,2,4-triazoles 6a,b. On the other hand, compounds 2a-c react with CS2-K2CO3 combination to furnish 1,3,4-thiadiazolo[3,2-c]-4-quinazolinium-2-mercaptides 7a-c. Treatment of the methiodide 8a with malononitrile in the presence of potassium t-butoxide provides a mixture of 2-[2-(2-nitrophenyl)-3H-quinazolin-4-ylidene]malononitrile 9 (24%) and 2-amino-5-(2-nirophenyl)pyrazolo[1,5-c]quinazoline-1-carbonitrile 10 (40%). The reaction between Schiff bases 11 derived from 2a and phenacyl bromide yields 2-benzoyl-1,3,4-thiadiazino[3,2-c]quinazolin-5-ium bromide derivatives 12a,b.
