Synthesis of 1-trichloeoacetyl-2-teichloeomethyl-1,3-diaza-2-cyclobuten-4-one

Conclusions Trichloroacetyl isocyanate reacts with trichloroacetonitrile on the type of 22-cycloaddition with the formation of 1-trichloroacetyl-2-trichloromethyl-1,3-diaza-2-cyclobuten-4-one.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimichesckaya, No. 10, pp. 2325–2326, October, 1972.     

New 1,3,4-thiadiazole derivatives from 1-benzylidenethiocarbonohydrazides and 3-Bromo-1-phenylprop-2-yn-1-one

3-Bromo-1-phenylprop-2-yn-1-one reacted with 1-benzylidenethiocarbonohydrazones in acetic acid or acetonitrile at room temperature (reaction time 3 h) to give in good yields the corresponding benzaldehyde N′-(5-benzoylmethyl-1,3,4-thiadiazol-2-yl)hydrazone hydrobromides which were converted into the free bases by treatment with aqueous ammonia.     

Synthesis of 3-aminoindan-1-one derivatives from 2-acetylbenzaldehydes and secondary amines by Mannich annulation

An acid-promoted 2-component Mannich annulation reaction of readily available acetylbenzaldehydes and secondary amines has been reported. The approach provides a simple and efficient method under mild conditions to synthesize 3-aminoindan-1-one derivatives in moderate to good yields.     

Synthesis and mesomorphic properties of some cyclohex-2-en-1-one derivatives

Mesomorphic properties of cyclohex-2-en-1-ones belonging to 14 different chemical structural types are compared and discussed. They were prepared by condensation of Mannich salts with 2-substituted acetoacetates or benzyl methyl ketones or acetylacetone in the presence of potassium hydroxide.     

Synthesis of 1-benzyloxypyrazin-2(1H)-one derivatives

Different approaches for the synthesis of 1-benzyloxypyrazin-2(1H)-one derivatives from simple amino acids have been investigated. A library of 33 precursors for the preparation of N-hydroxy pyrazinones was obtained in moderate to good yields.     

Selective,one-pot synthesis of 2,3,6-trisubstituted pyridine and 2-cyclohexen-1-one derivatives from bicyclic ketals

Boron difluoromethanesulfonate, prepared from 5 equivalents of trimethylsilyl methanesulfonate and 1 equivalent of boron trifluoride etherate, has proved to be an active Lewis acid catalyst for the one-pot transformation reaction of bicyclic ketals in the 6,8-dioxabicyclo[3.2.1]octane series to 2,3,6-trisubstituted pyridine or 2-cyclohexen-1-one selectively, depending on conditions. A 1,5-diketone was the reaction intermediate for both products. Pyridine was formed selectively by using a nitrile as a solvent or a reagent, but cyclohexenone was prepared in methylene chloride instead of a nitrile.     

Facile synthesis of 2H-indazole derivatives starting from the Baylis-Hillman adducts of 2-cyclohexen-1-one

Facile synthetic method of 2H-indazole derivatives was developed involving DDQ oxidation of pyrazoles, which were prepared starting from the Baylis-Hillman adducts of 2-cyclohexen-1-one.     

Piperidol derivatives of some aromatic acetylenes

Conclusions A number of acetylenic amines, representing piperidol derivatives, was synthesized, which are potential vasodilator agents.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 10, pp. 2254–2257, October, 1972.     

1, 2, 4-Triazol-3-one and its nitro and amino derivatives

Some possible methods of preparation of 1, 2, 4-triazol-3-one are explored. A new method of preparing it from semicarbazide hydrochloride and formic acid is worked out. Nitration of the triazolone gives 5-nitro-1, 2, 3-triazol-3-one, whose structure is proved.     

Synthesis of quinolizin-2-one and pyrido[1,2-a]azepin-2-one derivatives from difluoroboron complexes of aroylacetones and O-methyllactims

O-Methyllactims react at the methyl group of difluoroboron complexes of aroylacetones with the formation of condensation products, novel difluoroboron chelates of 1-aryl-4-(piperi-din-2-ylidene)butane-1,3-diones and 1-aryl-4-(azepan-2-ylidene)butane-1,3-diones, which upon the action of concentrated HCl in ethanol are transformed into the corresponding quino-lizin-2-one and pyrido[1,2-a]azepin-2-one derivatives.     

Benzoxazol-2 (3H)-one and 1,3,4-oxadiazol-2(3H) -one derivatives from substituted enaminones and ketoenamines

Enaminones and ketoenamines bearing a hydrazine type substituent undergo side chain thermal cyclization, the former into benzoxazol-2 (3H)-one derivatives and the latter into 1, 3, 4-oxadiazol-2 (3H)-one derivatives. Factors affecting such reactions are discussed.     

One-pot synthesis of some 2H-Pyran-2-one derivatives

A one-pot synthesis of various 2H-pyran-2-one derivatives 5–19 starting from methyl ketones 1 , N,N-dimethylformamide dimethyl acetal and N-acylglycines 3 in acetic anhydride is described.     

The syntheses of pteridin-2-one derivatives from diaminomaleonitrile (DAMN)

1,3-Dimethyl-4-iminopteridin-2-one, 1,3-dimethylpteridine-2,4-dione, 1-methylpteridine-2,4-dione, 4-alkoxy-1-methylpteridin-2-one, and 4-alkylamino-1-methylpteridin-2-one were synthesized from diaminomaleonitrile (DAMN) through pyrazine-2,3-dicarbonitrile. The synthetic procedures consist of the condensation of DAMN with glyoxal, the nucleophilic substitution of pyrazine-2,3-dicarbonitrile with methylamine, the reaction of 3-methylaminopyrazine-2-carbonitrile with electrophiles such as methyl isocyanate and methyl chloroformate in the presence of sodium hydride, and the transformation of 3-(methoxycarbonylmethyl)aminopyrazine-2-carbonitrile into the pteridine derivatives.     

Synthesis of 1,3,4-thiadiazin-2-one and 1,3,4-selenadiazin-2-one derivatives as new cardiotonic drugs

The synthesis of the new heterocycle 1,3,4-selenadiazin-2-one is described, based on the preparation of the analogue heterocycle 1,3,4-thiadiazin-2-one. The related cyclization between an α-haloketone and a thiocarbazate cannot readily be employed within the selenium series. Therefore a new route was developed based upon a diazotization/hydrolysis sequence of the related 2-amino-1,3,4-selenadiazine.     

Synthesis and structure of 4-arylspirodihydro-pyranochromen-2-one derivatives

Syntheses are reported for sulfur-and nitrogen-containing derivatives of 4-arylspiro-2-benzopyranones modified at the exocyclic oxygen atom. The structure of these products was demonstrated by correlational NMR spectroscopy. __________ Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 4, pp. 518–527, April, 2007.