Pyrimido [1,2-b]indazoles from 3-aminoindazoles and β-diketones

3-Aminoindazole and its hydrochloride react with β-diketones to give pyrimido [1,2-b]indazoles and their hydrochlorides.     

Synthesis of 2-hetaryl-2-(tetrahydrofuran-2-ylidene)acetonitriles

The reaction of azolylacetonitriles with γ-chlorobutyryl chlorides gave the corresponding 2-(1-R-1,3-di- hydro-2H-benzimidazol-2-ylidene)-, 2-(1,3-benzothiazol-2-ylidene)-, and 6-chloro-2-(4-methylthiazol-2-ylidene)-3-oxohexanenitriles. A study of the intramolecular cyclization of 2-(quinazolin-2-ylidene)-3-oxo-6-hexanenitriles and -heptanenitriles has led to the development of an efficient method for the preparation of 2-(quinazolin-2-yl)-2-(tetrahydrofuran-2-ylidene)acetonitriles. The (Z,E)-isomerism of the synthesized 2-hetaryl-2-(tetrahydrofuran-2-ylidene)acetonitriles was studied.     

General and Facial Synthesis of 2‐Amino‐5‐halogenpyrimidine‐4‐carboxylic Acids and Their Derivatives

A facile synthetic approach to 2‐amino‐5‐halogen‐pyrimidine‐4‐carboxylic acids from 5‐halogen‐2‐methylsulfonylpyrimidine‐4‐carboxylic acid by nucleophilic displacement of the methylsulfonyl group with primary and secondary aliphatic amines has been developed. The titled amino acids underwent decarboxylation, yielding 2‐amino‐5‐halogenpyrimidines. Starting from 2‐amino‐5‐chloropyrimidine‐4‐carboxylic acid chlorides, 2‐[5‐chloro‐2‐(amino)‐4‐pyrimidinyl]‐2‐oxo‐1‐(2‐pyridyl)‐ethyl cyanides were obtained in excellent yields.     

3-Amino-4-aryl-1(2H)-isoquinolones

3-Amino-4-aryl-1(2H)-isoquinolones have been synthesized by treating 2-halobenzamides with arylacetonitriles. The angle of rotation of the 4-phenyl grop has been determined.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 3, pp. 378–380, March, 1991.