Studies in the formation of heterocyclic rings containing nitrogen

Eight representative aromatic aldehydes with hydroxy, methoxy, nitro and chloro substituents have been condensed withs-diphenyl urea and ammonium acetate resulting in 2-keto-1, 3, 4, 6-tetra-aryl-hexahydro-s-triazines. The condensation of phenyl urea with five aldehydes and ammonium acetate, however, gave 1-phenyl-1:3-bis-(α-hydroxy aryl) ureas. The ultra-violet and infra-red spectra of these two types of compounds have been recorded.     

Studies in the formation of heterocyclic rings containing nitrogen

Proceedings - Mathematical Sciences - The condensation of 4-chloro-o-phenylenediamine with two moles of seventeen aromatic aldehydes under acidic conditions has been found to yield mono and...     

Studies in the formation of heterocyclic rings containing nitrogen

1, 3-Dibenzyl-2-substituted-5-chloro benzimidazolines have been prepared from N, N²-dibenzyl-4-chloro-o-phenylenediamine and various aldehydes. Pyrolysis of these benzimidazolines yielded 1-benzyl-2-substituted-5-chloro-benzimidazoles, by preferential elimination of benzyl group from the N, meta to chloro group. Structure of the pyrolytic products has been confirmed by comparison with authentic 5-chloro and 6-chloro isomers.     

Studies in the formation of heterocyclic rings containing nitrogen

The mode of formation of keto-hexahydro-s-triazines has been studied by conducting the reaction in two stages. The experiments revealed that the condensation with aromatic aldehydes is more complex, and the mechanism is not clear, although in the case of aliphatic aldehydes the step-wise formation of hexahydro-s-triazines has been reported.     

Studies in the formation of heterocyclic rings containing nitrogen: Part XXIII. Condensation ofo-aminobenzamide with aldehydes and schiff bases

N-Arylidene orthanilamides undergo isomeric cyclisation in acetic acid to the corresponding 2-aryl-1, 2, 3, 4-tetrahydro-4-oxoquinazolines. The u.v. and n.m.r. spectra of some of the arylidene derivatives and their isomeric tetrahydroquinazolines have neeb studied. Condensation ofo-aminobenzamide either with aromatic aldehydes in nitrobenzene or Schiff bases in acetic acid has yielded 2-aryl-4 (3H)-quinazolinones.     

Formation of heterocyclic rings containing nitrogen: Part XXVI—Condensation of pyridine 2, 3-diamine with aromatic aldehydes

Preparation of 3-arylideneamino-2-aminopyridines (I), 2-aryl-1H-2, 3-dihydroimidazo (4, 5-b) pyridines (III) and 2-aryl-1H-imidazo (4, 5-b) pyridines (IV), by the condensation of pyridine-2, 3-diamine with aromatic aldehydes under different conditions is described.     

Flavylium salts containing pyrone rings

Proceedings - Mathematical Sciences - Flavylium salts containing γ- and α-pyrone rings have been prepared by condensing 7-hydroxy-3-methoxy-flavone-8-aldehyde and umbelliferone-8-aldehyde...