Synthesis and Structure of Novel Thieno[2, 3‐d]Pyrimidine Derivatives Containing 1, 3, 4‐Oxadiazole Moiety

Abstract

The reaction of 5-(1-pyrrolyl)-4-methyl-2-phenylthieno[2,3-d]pyrimidine carbohydrazide 5 with CS 2 in the presence of pyridine afforded the 6-(2,3-dihydro-2-mercapto-1,3,4-oxadiazol-5-yl)-4-methyl-5-(1-pyrrolyl)-2-phenylthieno[2,3-d]pyrimidine 6, which reacted with methyl iodide in the presence of sodium methoxide to yield the 6-(2-methylthio-1,3,4-oxadiazol-5-yl)-4-methyl-5-(1-pyrrolyl)-2-phenylthieno[2,3-d]pyrimidine 7. The 6-(2-substituted-1,3,4-oxadiazol-5-yl)-2-phenylthieno[2,3-d]pyrimidine derivatives 9, 11 and 13 were obtained by the condensation of 6-(2-methylthio-1,3,4-oxadiazol-5-yl)-2-phenylthieno[2,3-d]pyrimidine 7 with appropriate secondary amines. The structure of the new compounds was substantiated from their IR, UV-vis spectroscopy, 1 H NMR, mass spectra, elemental analysis and X-ray crystal analysis.

Recent developments regarding the use of thieno[2,3-d]pyrimidin-4-one derivatives in medicinal chemistry, with a focus on their synthesis and anticancer properties

“…which was then reacted with CH 3 I in the presence of sodium methoxide to yield the 6-(2- i.e., a positive solvatochromism, which shows that the compound molecules were more polar in the excited state than in the ground state [42,43].…”

Thioxopyrimidine in Heterocyclic Synthesis III: Synthesis and Properties of Some Novel Heterocyclic Chalcone Derivatives Containing a Thieno[2,3‐d]pyrimidine‐Based Chromophore

“…According to Richter [48] and McLaren et al [49] the position of the color is distributed in the red-green area with hue angle ℎ ∘ 33.07-116.83 ∘ and radial chroma * of length 8. [35][36][37][38][39][40][41][42][43][44][45][46][47][48].08. Figure 1 shows a graph of CIE coordinates * versus * for selected dyes 6b, 6e, 6l, and 6n (an increasing * value represents an increase in redness, while a decrease in * represents a green hue shi).…”

“…Although a number of papers concerning the synthesis of chalcone compounds have been published, those containing a new heterocyclic system of thieno [2,3-d]-pyrimidinebased chromophores and application have not yet been reported. erefore, based on our previous works [37][38][39], we aim to report herein the preparation of a series of chalcone derivatives containing a thieno[2,3-d]-pyrimidinebased chromophore, and there was application to polyester �bers as disperse dyes. e spectral characteristics, dyeing properties, and colorimetric assessment of the dyes are also discussed.…”

Thioxopyrimidine in Heterocyclic Synthesis II: Novel Synthesis of Some Triazoles and Triazepine Derivatives with a Pyrimido[3,2:4,5]thieno[2,3‐d]pyrimidine Skeleton

“…In preceding papers [26][27][28][29], we have described the synthesis of some new pyrimido [2,3:4,3]pyrazolo[1,5-a]pyrimidines, 1,2,4-triazolo [1,5-a]pyrimidothieno [2,3-d]pyrimidine, and 1,3,4-oxadiazole-thieno [2,3-d]pyrimidines from 5-cyano-1,6-dihydro-4-methyl-2-phenyl-6-thioxopyrimidine 1 [26], respectively. In continuation of our studies [26][27][28][29][30], we report herein the synthesis of some new pyrimido[3 � ,2 � :4,5]thieno [3,2-e] [1,2,4]-triazolo [1,5-c]pyrimidines and pyrimido[3 � ,2 � :4,5]thieno [3,2:4,5]pyrimido [1,6b] [1,2,4]triazepine derivatives by making use of the key intermediate 7-amino-8-imino-pyrimido [3,2:4,5]thieno [2,3d]pyrimidine (10), easily obtained from the thioxopyrimidine 1. e substrate proved to be a versatile compound by virtue of its vicinal amino and imino functions, evaluating the reactivity in several cyclization reactions performed with the aim of obtaining new triazoles and triazepines with a conserved PTP core.…”