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The reaction of 2-hetarylacetonitriles with heterocyclic haloaldehydes

“…Hence the tetracyclic products (compound 10 and 1-aryl-3-methyl-1H-benzo [4,5]imidazo[1,2-a]-pyrazolo[4,3-e]pyridine-5-carbonitriles 7) are readily formed as a result of the regioselective intramolecular annelation of the heterocyclic fragment in the 3-(1-aryl-5-chloro-3-methyl-1H-4-pyrazolyl)-2-hetaryl-2-propenenitriles 9 and 8 respectively (prepared by condensation of 2-hetarylacetonitriles with 1-aryl-5-chloro-3-methyl-1H-4-pyrazolylcarbaldehydes). The results obtained by studying the intramolecular (het)arylation of derivatives based on 2-(4-oxo-3,4-dihydro-2-quinazolinyl)acetonitriles allow us to deduce that the main factor influencing the direction of attack in these reactions is the steric environment of the nitrogen atom to which this attack is directed.…”

“…It was of interest to study this reaction for 3-(halohetaryl)-2-(4-oxo-3,4-dihydro-2-quinazolyl)acrylonitriles. The latter were prepared by the reaction of quinazolylacetonitriles 1 with azine and azole series haloaldehydes.Reaction of 2-chloro-7-methyl-3-quinolinecarbaldehyde with 2-(1H-benzo[d]imidazol-2-yl)acetonitrile was studied in [3] and gave 7-methylbenzo[g]benzo [4,5]The reaction of 2-(4-oxo-3,4-dihydroquinazolin-2-yl)acetonitriles 1 with 2-chloro-3-quinolinecarbaldehydes 2 has not been studied before. It was found that heating the reaction mixture for 1.5-2 h resulted in the formation of 3-(2-chloroquinol-3-yl)-2-(4-oxo-3,4-dihydroquinazolin-2-yl)-2-propenenitriles 3 (Scheme 1).…”

“…Reaction of 2-chloro-7-methyl-3-quinolinecarbaldehyde with 2-(1H-benzo[d]imidazol-2-yl)acetonitrile was studied in [3] and gave 7-methylbenzo[g]benzo [4,5]…”

“…The authors of [3] reported that heating the starting materials in DMF in the presence of a 10% excess of pyridine gave the intramolecular cyclization product 3-methyl-1-phenyl-1H-benzo [4,5] of the condensation product 2-(1H-benzo[d]imidazol-2-yl)-3-(5-chloro-1,3-diphenyl-1H-4-pyrazolyl)-2-propenenitrile of type 8 formed in 74% yield by heating a mixture of 2-(1H-benzo[d]imidazol-2-yl)acetonitrile 6a in ethanol with the aldehyde mentioned above. By carrying out the reaction in the presence of piperidine it did not stop at the stage of formation of product 8 but the authors separated the type 7a cyclic product 1,3-diphenyl-1H-benzo [4,5]imidazo[1,2-a]-pyrazolo[4,3-e]pyridine-5-carbonitrile (Scheme 3) in 63% yield from the reaction mixture.…”

“…By carrying out the reaction in the presence of piperidine it did not stop at the stage of formation of product 8 but the authors separated the type 7a cyclic product 1,3-diphenyl-1H-benzo [4,5]imidazo[1,2-a]-pyrazolo[4,3-e]pyridine-5-carbonitrile (Scheme 3) in 63% yield from the reaction mixture. However, the characteristics and spectroscopic data for compounds 7,8 were not presented in [4].…”