Synthesis of 4-hydroxythieno[2, 3-d]pyrimidine derivatives

Condensation of 2-amino-3-ethoxycarbonylthiophenes with formide at 200° C gives a number of 4-hydroxythieno [2, 3-d]-pyrimidine derivatives.     

Synthesis and some transformations of 1, 2, 3, 4-tetrahydrophenothiazine derivatives

1,2,3,4-Tetrahydrophenothiazine derivatives were obtained from cyclic monoketones and 1,3-diketones and o-nitroarenesulfenyl chlorides. The alkylation, aminomethylation, and oxidation of the compounds obtained were studied.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 11, pp. 1509–1513, November, 1972.     

Synthesis of derivatives of 2-amino-3-ethoxycarbonylthiophene

A number of alkylidene esters are synthesized from the corresponding ketones and cyanoacetic ester, and treatment of the esters with sulfur in the presence of a catalytic amount of diethylamine gives 2-amino-3-ethoxycarbonylthiophene derivatives.     

Polynuclear heterocyclic compounds containing an indole fragment

Derivatives of 6,7,9,10,11,12-hexahydro-5H-indolo[3,2,1-d,e]phenazine and 1,2,3,4-tetrahydroindolo[1,2-a]quinoxaline were obtained by condensation of the sodium derivatives of 1-keto-1,2,3,4-tetrahydrocarbazoles and 2-aroylindoles, respectively, with-bromocyclohexanone dimethylketal. These compounds are converted to derivatives of indolo[1,2-a]-quinoxaline, 5,6-dihydroindolo[1,2-a]quinoxaline, and 8a,9,10,11,12,12a-hexahydro- and 5,6,7,7a,8a,9,10,11,12,12a-decahydro-8H-indolo[3,2,1-d,e]phenazine by dehydrogenation over a Raney nickel catalyst and reduction with sodium in alcohol.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1348–1352, October, 1970.     

Synthesis of substituted 2-amino-3-cyanopyrroles

A method was worked out for the preparation of substituted 2-amino-3-cyanopyrroles from N-acyl-α -amino ketones and malononitrile. Acyl derivatives of 2-amino-3-cyanopyrroles were obtained. A number of Mannich bases were synthesized by aminomethylation of 2-acetamido-3-cyano-4-phenylpyrrole.     

The Solubility of Sodium Sulfate and the Reduction of Aqueous Sulfate by Magnetite under Near-Critical Conditions

The solubility of Na₂SO₄ (s) (thenardite) and the interactions between magnetiteand aqueous Na₂SO₄ near the critical point of water have been determined in azirconium-alloy flow reactor at temperatures 350°C t 375°C and isobaricpressures 190 p 305 bar. The experimental solubility data are describedwell as a function of temperature and solvent density ₁ byln x(Na₂SO₄, aq.) = –10.47 – 27550/T +(4805/T) ln ₁.The interaction between magnetite and Na₂SO₄ (aq.) was examined from 250 to370°C at molalities near the saturation composition of Na₂SO₄ (s). While no solidreaction products were observed, HS^– (aq.) was observed to form above 350°Cby sulfate reduction, as a product of the reaction8 Fe₃O₄(s) + Na₂SO₄ (aq.) + H₂O(l)= 12 Fe₂O₃ (s) + NaHS (aq.) + NaOH (aq.).The reduction reaction appears to be controlled by surface reaction kinetics, ata level well below the equilibrium molality of HS^– (aq.). Metallic iron reactedwith Na₂SO₄ (aq.) in a similar fashion at temperatures above 350°C, to yieldhigher molalities of HS^– (aq.).     

2-methyl-3-ethoxycarbonyl-4-hydroxythiophene in the vilsmeier reaction

Continuing our investigation of the properties of 2-methyl-3-ethoxycarbonyl-4-hydroxythiophene (I) [1], we found that it readily undergoes electrophilic substitution reactions. We studied the behavior of I under the conditions of the Vilsmeier reaction. The structures of the reaction products depend on the temperature conditions: at 30–35°C, 2-methyl-3-ethoxycarbonyl-4-hydroxy-5-formylthiophene (H) is formed in 74% yield while 2-methyl-3-ethoxycarbonyl-4-chloro-5-formylthiophene (III) is formed in 50% yield at 100°. The reaction of I with dimethylbenzamide and phosphorus oxychloride gives 2-methyl-3-ethoxycarbonyl-4-hydroxy-5-benzoylthiophene (IV) in 41% yield.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 3, p. 427, March, 1972.