Synthese von 2,4‐Diamino‐thieno[2,3‐d]pyrimidin‐Derivaten

Abstract

Synthesis of 2,4-Diamino-thieno[2,3-djpyrimidinesCondensation of 2-aminothiophene-3-carbonitrile (4) with guanidine or sequential addition of CS, and NH, 1. Einleitung. -Nahezu alle Dihydrofolatreduktase-Hemmer lassen sich von 2,4-Diaminopyrimidin ableiten. Beispiele sind Trimethoprim (l), welches in der antibakteriellen Chemotherapie gebraucht wird, das Zytostatikum Methotrexat@ (2) und Pyrimethamin (3), ein Bestandteil des Antimalaria-Mittels Fansimep.

Synthesis Of Some New Thieno[2,3-D]Pyrimidin-4- Amine Derivatives

“…10 Various methods have already been proposed for the synthesis of these compounds and the most general ones involves cyclocondensation of suitably functionalized thiophenes with different electrophiles such as chloroformamidine," α-substituted acetonitriles, 12 formic acid, 13 phosgen, 14 ethyl chloroformate 14 and guanidine. 15 To the best of our knowledge, cyclocondensation of 2-amino-4,5-dimethylthiophene-3-carbonitrile 1 with aryl nitriles for the synthesis of 2-aryl-5,6-dimethylthieno[2,3-d]pyrimidin-4-amines 3a-f has not been reported in the literature. Prompted by these findings and due to our interest in the synthesis of new heterocyclic compounds with potential biological activities 16 " 26 and in continuation of our work on the synthesis of new thieno[2,3-d]pyrimidine derivatives, 27 " 29 we report herein a convenient synthesis of some new 2-aryl-5,6-dimethylthieno[2,3-d]pyrimidin-4-amines 3a-f that might be of pharmacological importance.…”

Investigation into the reaction of 2‐amino‐4,5‐dimethylthiophene‐3‐carboxamide with iso(and isothio)cyanates under microwave irradiation

“…Also, some thieno [2,3-d]pyrimidines show central nervous system depressing activity [7] and are useful as muscle relaxants [8], sedatives [8], diuretics [9], pesticides, and herbicides [10]. Various methods have already been proposed for the synthesis of these compounds, and the most general ones involve cyclocondensation of suitably functionalized thiophenes with different electrophiles such as chloroformamidine [11], α-substituted acetonitriles [12], formic acid [13], phosgene [14], ethyl chloroformate [14], and guanidine [15]. To the best of our knowledge, reaction of 2-amino-4,5-dimethylthiophene-3-carboxamide 1 with isocyanates and isothiocyanates for the synthesis of thieno [2,3-d]pyrimidines under microwave irradiation has not been reported in the literature.…”

Synthesis of Some New 2-Arylthieno[2,3-d]Pyrimidin-4(3H)-One Derivatives

“…Furthermore, a number of these compounds were found to exhibit CNS depressing 7 and DHFR inhibitory activities 8 and are useful as muscle relaxants, 9 sedatives, 9 diuretics, 10 pesticides and herbicides. 11 Various methods for the synthesis of these compounds have been reported in the literature that mainly involve cyclocondensation of suitably functionalised thiophenes with different electrophiles such as chloroformamidine, 8 α-substituted acetonitriles, 12 formic acid, 13 phosgen, 14 ethyl chloroformate, 14 guanidine 15 and nitriles. 16 To the best of our knowledge, reaction of 2-amino-4,5-dimethylthiophene-3carboxamide 1 with aroyl halides and isolation of intermediates has not been reported in the literature.…”