Condensation of N-3-substituted 5-pyrazolones with esters of β-keto acids. Synthesis of pyrano[2,3-c]pyrazol-6-ones

N-Substituted 5-pryazolones undergo thermal condensation with esters of β-keto acids, losing water and alcohol molecules, to form N-substituted pyrano[2,3-c]pyrazol-6-ones. The pyran ring in these products is readily cleaved by the action of alkali to give the corresponding salts of unsaturated acids. __________ Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 3, pp. 367–372, March, 2006.     

Synthesis ofω-substituted 3-alkylorotic acids

3-(-Phthalimidoalkyl)-5-carbethoxymethylenehydantoins were synthesized by the reaction of-phthalimidoalkylureas with ethyl oxalacetate and then converted to 3-(-aminoalkyl)orotic acids. Condensation of the latter with 6-chloropurine yielded 3-[-(6-purinylamino)alkyljorotic acids.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 3, pp. 397–399, March, 1971.     

Synthesis of esters of oxocaprylic acids

Conclusions On hydrogenation over Pt-C in the vapor phase (240–250°), esters of -(5-methylfuryl)-propionic acids undergo hydrogenolysis of the C-O bond in the furan ring and are converted into the corresponding esters of-oxocaprylic acid (35–50%) and-oxocaprylic acid (25–35%).Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 2, pp. 420–422, February, 1967.     

Synthesis of esters of allenic acids

Conclusions Starting with 1,1-dimethoxy-1-buten-3-yne, a method was proposed for the synthesis of the esters of -hydroxyallenic acids and of a 5-dialkylamino-2,3-pentadienoic acid.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 9, pp. 2089–2090, September, 1971.     

Synthesis and reactions of 2-substituted ethyl N-alkylmalonylhydroxamic acids

Alkylation of O-silylated N-alkylmalonylhydroxamic acids provides a method for the synthesis of 2-substituted N-alkylmalonyl hydroxamic acids. The substituent at C-2 does not materially change the chemistry of the alpha-lactam intermediates produced from them. They can be converted to unsymmetric ureas and hydantoins in high yields. The addition of unsaturated substituents at C-2 is used to produce cyclic ureas containing medium rings via RCM reactions.     

Synthesis of inulin esters of phenylcarboxylic acids

Inulin esters were synthesized containing residues of ferulic, p-hydroxycinnamic, and vanillic acids with a maximum degree of substitution of 1.1. The inulin acylation was carried out with chlorides of 4-acetoxy derivatives of the corresponding hydroxyphenylcarboxylic acids in a heterogenic water-organic environment. The removal of the protecting acetyl group at the phenol hydroxyl was carried out by treating with pyrrolidine or ammonium acetate. The solubility of the esters obtained was evaluated.     

Synthesis of choline esters of carboranecarboxylic acids

Conclusions The choline esters of a number of o- and m-carborane mono- and dicarobxylic acids were synthesized by reacting the corresponding acid chlorides with dimethylaminoethanol in the presence of triethylamine.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 11, pp. 2606–2608, November, 1976.     

Synthesis and properties ofsym-triazene derivatives 13. Synthesis of 6-substituted 2,4-dialkyl(aryl)thio-sym-triazenes from imino esters of carboxylic acids

6-Substituted 2,4-dialkyl(aryl)thio-sym-triazenes are synthesized by condensation of imino esters of carboxylic acids with thiocyanates.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 8, pp. 1125-1128, August, 1994.For paper 12, see [1].     

Synthesis of unsaturated esters of m- and p-carboranedicarboxylic acids

Conclusions Some unsaturated diesters of the m- and p-carboranedicarboxylic acids, which can be used in polymerization and copolymerization reactions, were synthesized and characterized.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 8, p. 1904, August, 1982.     

Synthesis of unsaturated esters of pyridine- and quinolinedicarboxylic acids

The divinyl, diallyl, and dipropargyl esters of pyridine-2,4-, pyridine-2,6-, and quinoline-2,4-dicarboxylic acids and the divinyl and dipropargyl esters of pyridine-2,5-dicarboxylic acid have been synthesized.