ABSTRACT
Mixtures of malononitrile, aromatic aIdeyde, and 4-nitrosoantipyrine [5] were interacted in ethanolic piperidine solutions, in one-pot reaction to give the corresponding 6-aryl-1-methyl-3-oxo-2-phenyl-2, 3-dihydro-1H-pyrazolo [4, 3-b] pyridine-5 carbonitriles [3] or their corresponding 6-alkyl-4-hydroxy- 1-methyl-3-oxo-2-phenyl- 1, 2, 3, 4-tetrahydro-SH-pyrazolo [4,-3-b] pyridine-5, 5-dicarbonitrile [4] depending on reaction temperature. However, carrying out the above reaction using 3-methyl-4-oximmno-1-phenyl-1H-pyrazolin-5-one [15b] instead of compound [5], the corresponding 6-aryl-7a-hydroxy-3-methyl-1-phenyl- 1, 7a-dihydro-pyrazolo [4, 3-c] [1, 2] oxazine-7-carbonitrile [17] were obtained. Chalcones [9] were reacted also with compounds [5] and [15b], to afford the corresponding 5-aroyl-6-aryl-1-methel-2phenyl-1, 2-dihydro-3H-pyrazolo [4, 3-b] pyridine-3 ones [12], and aryl [6-aryl-3-methyl-1-phenyl-1, 4-dihydropyrazolo [4, 3-c] [1, 2] oxazin-5-yl] methan-ones [20]. Aniline hydrochloride was condensed with compounds [3] in acetic acid to give the corresponding N-phenyl-2, 3-dihydro-1 H-pyrazolo [4, 3-b] pyridine-5-carboximidamides 6, which were converted into the corresponding 1-phenyl-1 H-imidazole-4, 5-diones [7] by their reaction with oxaly 1 chloride. However, on reaction of ethylenediamine with compounds [3] in the presence of p-toluenesulfonic acid, the corresponding 6-aryl-5-[4, 5-dihydro-1 H-imidazol-2-y1]-1-methyl-2-phenyl-1, 2-dihydropyrazolo [4, 3-b] pyridin-3-ones [8] were obtained