Microwave-assisted ring closure reactions: Synthesis of 8-substituted xanthine derivatives and related pyrimido- and diazepinopurinediones

Abstract

Background

Xanthine scaffold: scope and potential in drug development

“…Traube synthesis mechanism is the widely used industrial method for synthesis in which 5, 6-diaminouracils formed from urea or N-substituted urea and followed by cyclization i,e. ring closure [ 11 , 29 , 78 , 79 ]. Orthogonal safety-catch protection has been another strategy for synthesizing these derivatives [ 12 , 80 ].…”

“…In recent years, the scale of clinical applications on these derivatives has been augmented. This has helped in exploring the significance of these derivatives in various therapeutics applications such as adenosine receptor antagonists, inducers of histone deacetylase activity, antitumor drugs, anti asthmatic drug, psycho-stimulant drug etc [ 10 , 11 , 12 , 13 , 14 ]. The wider pharmaceutical applications of natural xanthine derivatives has prompted medicinal chemist or pharmaceutical companies to go for certain changes over lead molecule to develop more specific compounds using synthesis methodologies [ 15 , 16 , 17 , 18 , 19 ].…”

7-Substituted pyrrolo[2,3-d]pyrimidines for the synthesis of new 1-deazapyrimido[1,2,3-cd]purines

“…Found: 42.85;H,4.85;Cl,8.51; N, 13.39. -8-(dimethylamino)-4-hydroxy-4,5-dihydro-3H-2a,7-diaza-5a-azoniaacenaphthylene perchlorate (7) ,4.43;Cl,9.75;N,15.40. Found: 39.72;H,4.46;Cl,9.83;N, perchlorate (8).…”

“…A natural pyrimido [1,2,3-cd]purine-8,10(9H)-dione was for example isolated from the South China Sea gorgonian Subergorgia suberosa [5]. Tricyclic xanthine derivatives were described as selective adenosine A1 receptor antagonists (PSB-63) [6][7][8], and purine cyclonucleosides modified with sugar residues were reported to exhibit antiviral properties [9][10][11].…”

Synthesis and Characterization of 3 - Substituted Coumarin

“…Hydrazine hydrate (2-3 ml) is added to the (0.01mol) of the compound (k1) found in absolute ethanol (10ml), then refluxed for (4hs.). After that the formed solid was cooling and filtered then recrystallized from (methanol: ethyl acetate) (1:1) [10]. The physical properties of (K2) are listed on Table (1).…”