Recyclization of Acylation Products of 2-Aryl-5-hydrazino-4-(dialkoxyphosphoryl)oxazoles

Russian Journal of General Chemistry -     

Alkylation of 4-(phenylthio)-1<Emphasis Type="Italic">H</Emphasis>-pyrazol-5-ols with methyl bromoacetate

Alkylation of 4-(phenylthio)-1H-pyrazol-5-ols with methyl bromoacetate has afforded a series of phenyl pyrazolyl sulfides which have been oxidized into sulfones. The resulting esters have been hydrolyzed into the corresponding acids. The synthesized compounds potentially exhibit biological activity.     

Synthesis and Transformations of 4-Phosphorylated 2-Alkyl(aryl)-5-hydrazinooxazoles

Treatment of 1-phosphorylated 2,2-dichloroethenylcarboxamides with excess hydrazine hydrate gives in high yields phosphorylated derivatives of 2-alkyl(aryl)-5-hydrazinooxazoles containing the P(O)(OCH₃)₂, P(O)(OC₂H₅)₂, and P⁺(C₆H₅)₃ClO₄ ^- groups in the 4-position of the ring. The presence of the hydrazine group in these oxazole derivatives was confirmed not only by the spectral data, but also by the reactions with p-toluic aldehyde, p-toluic chloride, and phenyl isothiocyanate.     

Synthesis of 1-aryl-2-[2-(dimethylamino)ethyl]-1,2-dihydrochromeno[2,3-c]pyrrole-3,9-diones and their analogs

Methyl o-hydroxybenzoylpyruvate heated with N,N-dimethylethylenediamine and aromatic aldehydes affords in a high yield 5-aryl-3-hydroxy-4-(2-hydroxyphenyl)-1-[2-(dimethylamino)ethyl]-1,5-dihydro-2H-pyrrol-2-ones, which easily split off water at boiling in acetic acid and are converted into 1-aryl-2-[(2-dimethylamino)ethyl]-1,2-dihydrochromeno[2,3-c]pyrrol-3,9-diones. The developed route of synthesis provides a wide range of derivatives of 1-aryl-2-[ω-(dialkylamino)alkyl]-1,2-dihydrochromeno[2,3-c]pyrrole-3,9-diones.     

Alkylation of 1-Alkyl-3-methyl-1,4-dihydropyrazolo[4,3-<Emphasis Type="Italic">c</Emphasis>]pyrazoles with Halocarboxylic Acids Esters

A preparative method for the synthesis of 1-alkyl-3-methyl-1,4-dihydropyrazolo[4,3-c]pyrazoles was developed. The alkylation of the obtained compounds with halocarboxylic acid esters was also investigated. A principal possibility of creating libraries of compounds based on pyrazolo[4,3-c]pyrazole derivatives was shown.     

Synthesis and Transformations of Two Types of 4-Phosphorylated Aldehydes of the Oxazole Series

Available N-(1,2,2,2-tetrachloroethyl)dichloroacetamide selectively reacts with trialkyl phosphites and triphenylphosphine, which was used for preparing polycentered electrophilic agents unusually reacting with piperidine and morpholine in the presence of water to give in high yields 4-dialkoxyphosphoryl- or 4-triphenylphosphonio-substituted oxazole-2-carbaldehydes containing piperidine or morpholine moiety in the 5-position. Their structure was determined by spectroscopy and also by chemical transformations into phenylhydrazones, thiosemicarbazones, aminals, and other functional derivatives of these two types of phosphorus-containing aldehydes of the oxazole series.