ChemInform Abstract: SYNTHESIS AND BIOLOGICAL ACTIVITY OF TETRAZOLO(1,5‐C)THIENO(3,2‐E)PYRIMIDINES

Abstract

Aus den Aminothiophencarbonsäureestern (I) und den Nitrilen (II) werden die Thienopyrimidinone (III) erhalten, die in die Hydrazin‐Derivate (V) übergeführt werden.

Synthesis and isomerization of thienotriazolopyrimidine and thienotetrazolopyrimidine derivatives with potential anti-inflammatory activity

“…The synthesis of thieno [1,2,4]triazolopyrimidines has attracted attention of many investigators [1][2][3][4][5][6][7][8][9][10][11] and since the first synthesis of thieno [3,2-e][1,2,4]-triazolo [4,3-c]pyrimidines by Robba et al [12], many derivatives have been described and proved to have pronounced biological activities [2,7,13,14]. Previous observations revealed that the above pyrimidine derivatives can isomerize under different suitable reaction conditions to the thermodynamically more stable thieno [3,2-e] [1,2,4]triazolo- [1,5-c]pyrimidines [3][4][5][6][7].…”

Microwave-Assisted and Conventional Synthesis of Benzothieno [3,2-e] [1,3,4] triazolo[4,3-c]pyrimidines: A Comparative Study

“…6,7 In view of these fascinating and encouraging results and in continuation of our work on biologically active nitrogen and sulfur heterocycles, 8 we have synthesized some thienopyrimidine and triazolothienopyrimidine derivatives. Addition to the conventional method the microwave irradiation technique has also been employed for the synthesis of some thienopyrimidines (2,3,4) and triazolothienopyrimidines (5a−c) and the results have been compared. Microwave irradiation provides an alternate to conventional heating as it utilizes the ability of liquids or solids to transform electromagnetic energy into heat.…”

“…Benzothieno [2,3-d]pyrimidines (2,3,4) and benzothieno [3,2-e] [1,3,4]triazolo [4,3-c] pyrimidines (5a−c) were synthesized from the precursor 2-amino-7-oxo-4,5,6,7-tetrahydro-1-benzothiophene-3-carbonitrile 1 by employing the conventional method as well as the microwave irradiation technique. The precursor 2-amino-3-cyanothiophene analogue 1 was synthesized by employing the well-known Gewald reaction.…”

Microwave-Assisted Synthesis of Novel-5-Substituted-2,3-dihydroimidazo[1,2-c]thieno[3,2-e]pyrimidines

“…19 However, we have prepared them in a single pot reaction from 2-amino-3-carbethoxy-4,5-disubstituted/tetrasubstituted thiophenes 1 using nitriles to give the intermediates 2-substituted-4-hydroxythieno[2,3-d]pyrimidines; subsequent heating under reflux in phosphorous oxychloride gave compounds 2a-j in 40%-60% yields (Scheme).…”

“…Calcd for C19 H 21 N 3 OS: C, 67.23; H, 6.24; N, 12.38. Found: C, 67.15; H, 6.15; N, 12.38.2-Pyridinyl-4-[(2-hydroxy)ethyl]amino-5,6,7,8-tetrahydrobenzo(b)thieno[2,3-d]pyrimidine (3j)Yield: 2.60 g (80%).Mp 133-134°C.1 H NMR (CDCl 3 ): d = 1.68-1.89 (m, 4 H, CH 2 -6, -7), 2.67-2.98 (m, 4 H CH 2 -5, -8), 3.80-3.91 (t, 2 H, J = 10.0, -CH 2 OH), 3.96-4.11 (t, 2 H, J = 9.4, -CH 2 NH-), 4.56-4.97 (br s, 1 H, OH, D 2 O exchangeable), 5.59-6.57 (br s, 1 H, NH, D 2 O exchangeable), 8.21-9.10 (m, 4 H, C 5 H 4 N).…”