Thieno[2,3-d]pyrimidin-4-ones 1. Condensation of 2,3-dimethyl- and 2,3-tri-, 2,3-tetra-, and 2,3-pentamethylene-7,8-dihydro-pyrrolo[1,2-a]thieno[2,3-d]pyriminidin-4(6H)-ones with aromatic aldehydes and furfural

Abstract

Among the large number of compounds of the thieno[2,3-d]pyrimidin-4-one series annelated at both heterocycles, derivatives of type I have been little studied. At the same time, among them are known substances which possess various biological activities (fungicidal, bactericidal, anti-inflammatory, etc.) [3-9], which shows potential for further synthesis and the study of properties of substances with similar structures.The objective of the present work is the synthesis of new derivatives of type I. They are traditionally synthesized from 2-amino-3-ethoxycarbonyl-4,5-disubstituted thiophenes by condensation with lactams [10,11] or O-alkyl esters of lactams [3], and also from cyclic ketones by the Gewald reaction [12,13]. Oxidation [14,15] and formylation [16,17] of such compounds occurs exclusively at the CH 2 group of ring A connected with the heterocyclic system of rings B and C at position 2.

2‐substituted tricyclic oxazolo[5,4‐d]pyrimidine library: Design, synthesis, and cytotoxicity activity

“…In recent years, we have synthesized and biologically evaluated several benzo‐ and thieno[2,3‐ d ]pyrimidines [29–34]. These are benzo‐ or thio‐analogues of the oxazolo[5,4‐ d ]pyrimidine scaffolds.…”

Furo[2,3‐d]pyrimidines as Mackinazolinone/Isaindigotone Analogs: Synthesis, Modification, Antitumor Activity, and Molecular Docking Study

“…These compounds are used as intermediates toward the synthesis of target arylidenes. Several pathways were reported toward the formation of arylidene derivatives via reactions of aldehydes and activated methylene‐containing heterocycles [37,49–51] . The screening of appropriate conditions for condensation furo[2,3‐ d ]pyrimidinone ( 6a ) with benzaldehyde is reported in Table 1.…”

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

“…• In addition, scientists from various countries [4][5][6][7][8], as well as our own research group, have conducted extensive studies of TPs in recent years, including important research into the synthesis, characterization, and biological screening of TPs [9][10][11][12][13][14][15][16].…”

“…In those reactions, they used aldehydes with an electron-withdrawing (EWG) NO 2 group, allowing the reactions to be stopped at a stage where the products of the electrophilic addition reactions are racemates, i.e., molecules containing an asymmetric carbon atom in position 8 or 9 83, and wherein aromatic aldehydes with an electron-donating group (EDG) substituent 9-arylidene derivatives 84 were formed exclusively (Scheme 22, a) [9,10]. Moreover, several novel compounds were demonstrated for X-ray analysis [11][12][13].…”