M. V. Dorogov

Synthesis of the Substituted 3-Cyclobutene- 1,2-diones

Abstract A convenient synthesis of the novel squaric acid derivatives is reported. Unsymmetrically substituted 3,4‐diamino‐3‐cyclobutene‐1,2‐diones and 3‐amino‐4‐hydroxy‐3‐cyclobutene‐1,2‐diones were prepared by interaction of diethyl squarate with different nucleophilic reagents such as alkali, primary and secondary amines and amino acids. Substituted 3‐amino‐4‐aryl‐3‐cyclobutene‐1,2‐diones were synthesized by interaction of squaryl dichloride with different arenes followed by arylsquarylation of amines. Efficient procedures were developed for consequent substitution of ethoxy groups in diethyl squarate and chlorine atoms in squaryl dichloride. The synthesized compounds have a great potential of bioactivity and are useful objects for biomedicinal screening.

Synthesis of 7-sulfamoyl-substituted 2 -oxo -2,3,4,5 -tetrahydro -1H-benzo[b]azepines

Abstract Sulfochlorination of 2‐оxo‐2,3,4,5‐tetrahydro‐1H‐benzo[b]azepine led to regioselective formation of the corresponding 7‐chlorosulfonyl derivative. Starting from this reagent, a large number of substituted 2‐oxo‐7‐sulfamoyl‐2,3,4,5‐tetrahydro‐1H‐benzo[b]azepines were obtained. This approach is amenable to combinatorial production of the title compounds, which possess promising therapeutic potential.

An Efficient Chemoenzymatic Process for Preparation of Ribavirin

Ribavirin is an important antiviral drug, which is used for treatment of many diseases. The pilot-scale chemoenzymatic process for synthesis of the active pharmaceutical ingredient Ribavirin was developed with 32% overall yield and more than 99.5% purity. The described method includes the chemical synthesis of 1,2,4-triazole-3-carboxamide, which is a key intermediate and enzyme-catalyzed transglycosylation reaction for preparation of the desired product. 1,2,4-Triazole-3-carboxamide was synthesized from 5-amino-1,2,4-triazole-3-carboxylic acid by classical Chipen-Grinshtein method. Isolated from E. сoli BL21(DE3)/pERPUPHHO1 strain the purine nucleoside phosphorylase was used as a biocatalytical system. All steps of this process were optimized and scaled.

Synthesis of sulfonate derivatives of 4-heteryl-isoxazoles

Synthesis procedure of 3,5-dimethyl-4-heteryl-isoxazoles by reaction between heterocyclic aldehydes and nitroethane in the presence of base was developed. Sulfochlorination of the resulting compounds was studied.

A Convenient Synthesis of Novel 3-(Heterocyclylsulfonyl)propanoic Acids and their Amide Derivatives

A large number of novel 3-(heterocyclylsulfonyl)propanoic acids and their amide derivatives were prepared in good yields and excellent purity starting from the corresponding heterocyclic compounds. At first, chlorosulfonates were generated by reaction of initial heterocycles with various sulfonating and chlorinating agents followed by their conversion into sodium sulfinates. Treatment of sulfinates with acrylic acid smoothly afforded a series of sulfonylpropionates, which were used as convenient reagents for the preparation of a large number of the corresponding carboxamide derivatives.