Anwar Amer

Synthesis and Reactions of Some New Thiazolylpyrazole Derivatives and Related Compounds

Thiazolylpyrazoles 2-7 were prepared from the reaction of 2-hydrazino-4-phenylthiazole (1) with yielidenenitriles; S,S- or N, S-acetals or ethoxymethylenemalononitrile. 5-Amino-1-(4-phenyl-thiazol-2-yl)-1H-pyrazole-4-carbonitrile (7) reacted with phenyl isothiocyanate, carbon disulphide, formic acid, and formamide to furnish the pyrazolopyrimidines 8, 9, 16, and 17, respectively. Reaction of compound 7 with malononitrile afforded pyrazolopyridine 10, while its reaction with acetic anhydride, acetyl chloride, sulfuric acid, and triethylorthoformate gave thiazolylpyrazoles 12, 13, 15, and 18, respectively.

New Route for the Synthesis of Pyrazole, Triazole, Triazine, and Triazepine Derivatives

Abstract N,N′‐Diphenylpiperidine‐1‐carbohydrazonamide 1 was prepared and treated with halo compounds, active nitriles, diethylhy malonate, ketones, CS2, phenylisocyanate, phenylisothiocyanate, LR, ethyl 2‐cyano‐3,13‐dithiomethylacetate, and benzylidenenitriles to give the corresponding triazines 2–4, pyrazoles 5 and 6, triazoles 7, 8, and 10, triazaphosphole 11, and triazepines 12 – 14, respectively.

New route for the synthesis of new cyanoimino- and cyanoaminopyrimidines

A novel series of 4-aryl-2-cyanoimino-3,4-dihydro-1H-pyrimidines (aryl-CIDHPMs) was synthesized using a new method via the one-pot three-component reaction of cyanoguanidine with malononitrile and aromatic aldehydes using sodium methoxide as catalyst. These new aryl-CIDHPMs were also prepared by a classical route via reaction of cyanoguanidine with the corresponding arylidenemalononitriles under our conditions. In the same manner, the reaction of cyanoguanidine with cyclohexylidenemalononitrile and/or isatinylidenemalononitrile afforded new spiro-pyrimidines 9 and 10, respectively. A new series of polyfunctionalized 2-cyanoaminopyrimidines was obtained from the reaction of cyanoguanidine with cinnamaldehyde and/or ethoxyalkylenemalononitriles.Graphical Abstract

Utility of Hydrazinopiperidinomethanethione in Synthesis of Thiadiazole, Thiadiazine, and Pyrazole Derivatives

Hydrazinopiperidinomethanethione 2 was prepared and reacted with active halo compounds, carbon disulfide, phenyliso-thiocyanate, ylidenenitriles, and N,S-acetyls to give thiadiazine 4–7 , thiadiazole 8–10 , and pyrazole 11,13 , 14–17 derivatives, respectively.

A regioselective and convenient one-pot multicomponent synthesis of 9-amino-3,5-diaryl-4,9-dihydro-5H-[1,2,4]triazolo[5,1-c][1,2,4]triazepine-8-thiol

ABSTRACT An efficient and environment-friendly procedure for the synthesis of a new series of nitrogen bridge-head [1,2,4]triazolo[5,1-c][1,2,4]triazepine derivatives through one-pot three-component reaction of polyfunctional triazole with aromatic aldehydes and acetophenone derivatives using alcoholic sodium hydroxide solution. The same new products were prepared in classical route through reaction of triazole with the corresponding chalcones under the same conditions. GRAPHICAL ABSTRACT

Utility of bis(methylthio)methylene malononitrile as a synthon in the synthesis of new poly-functionalized cyanoiminopyrimidines

A new series of 4-(alkyl/arylamino)-6-amino-5-cyano-2-cyanoimino-1H-pyrimidine was obtained via one-pot three-component reaction of bis(methylthio)methylene malononitrile, primary amines, and cyanoguanidine using sodium ethoxide as basic catalyst. The same new products were prepared by classical route via reaction of (alkyl/arylamino)(methylthio)methylene malononitrile with cyanoguanidine in presence of sodium ethoxide. In absence of amines, bis(methylthio)methylene malononitrile reacts directly with cyanoguanidine in presence of sodium ethoxide to give 4-ethoxy-2-cyanoimino-1H-pyrimidine. On the other hand, multicomponents reaction of bis(methylthio)methylene malononitrile with cyanoguanidine and binucleophilic β-hydroxyamines and/or ortho-phenylenediamine gave perspective 4-methyl- and/or 5-methyl-1,3-oxazolidin-2-ylidenemalononitrile and 1,3-dihydro-2H-benzimidazol-2-ylidenemalononitrile, which are inactive compounds toward reaction with cyanoguanidine to give the expected 4-(alkyl/arylamino)-2-cyanoimino-1H-pyrimidines.Graphical abstract