β-Enaminonitriles in heterocylic synthesis: Synthesis of new tetrahydropyridinethione, pyridopyrimidines, pyridotriazines and dihydropyridines

Abstract

The chemistry of enaminonitrile and enaminone derivatives has been explored for the synthesis of heterocyclic compounds. A tetrahydropyridinthione was prepared from the reaction of 2aminocrotononitrile with cyanothioacetamide. This compound reacted with electrophilic reagents and isothiocyanates to yield a number of heterocyclic compounds.

Efficient Utilization of 6-Aminouracil to Synthesize Fused and Related Heterocyclic Compounds and Their Evaluation as Prostate Cytotoxic Agents with Cathepsin B Inhibition

“…In addition to a multiplet at δ 6.30 -6.38 ppm due to phenyl-C 5,6 protons. Moreover, the behavior of compound 1 towards isothiocyanate reagent was investigated to proceed typical to literature [63] [64]. Compound 1 was refluxed with phenyl isothiocyanate in pyridine to yield the acyclic thiourea derivative 17 which its 1 H NMR spectrum revealed the presence of two deuterium oxide exchangeable singlets at δ 8.90 and δ11.63 ppm due to uracil-C 6 -NH and NH-phenyl protons; respectively.…”

“…In addition to a singlet at δ 7.65 ppm due to pyrimidine C 6 proton. Finally, compound 1 was refluxed with acetyl isothiocyanate in dry acetone [63] triazine derivative 22 that is assumed to be formed through formation of the thiourea intermediate 22' that underwent tautomerism and subsequent cyclocondensation to yield compound 22. 1 H NMR spectrum of compound 22 exhibited a singlet at δ 2.05 ppm due to methyl protons.…”