Abstract A convenient synthesis of some novel 6-amino-4-aryl-1-phenyl-3-pyridin-4-yl-1, 4- dihydropyrano [2, 3-c] pyrazole-5-carbonitriles (3a, b) and 5-chloro-1-phenyl-3-pyridin-4-yl- 1H-pyrazole-4-carbaldehyde (4) is described. Compound 4 was obtained by the reaction of 2-phenyl-5-pyridin-4-yl-2, 4-dihydropyrazol-3-one (1) with dimethylformamide and phosphorus oxychloride under Vilsmeier-Haack reaction conditions. Compound 4 was ...
