A facile preparation of some novel class II mesoionic xanthine acyclonucleosides

Abstract

The synthesis of the first examples of Class II mesoionic xanthine acyclonucleosides is described. A series of mesoionic anhydro‐(8‐methoxyalkyl‐5‐hydroxy‐7‐oxothiazolo[3,2‐a]pyrimidinium hydroxides), Class II mesoionic analogs isoconjugate with xanthine, were prepared by the thermal condensation of methoxyalkyl‐2‐aminothiazoles with substituted bis(2,4,6‐trichlorophenyl)malonic esters. The memoxyalkyl‐2‐aminothiazoles were prepared via an aromatic nucleophilic substitution reaction between 2‐bromothiazole and the appropriate methoxyalkylamine in excess. The resulting 8‐methoxyalkyl‐substituted mesoionic xanthines were demethylated using iodotrimethylsilane in acetonitrile at room temperature to afford the corresponding mesoionic anhydro‐(8‐hydroxyalkyl‐5‐hydroxy‐7‐oxothiazolo[3,2‐a]pyrimidinium hydroxides) as the Class II mesoionic xanthine acyclonucleosides.

Mild Pd-Catalyzed Aminocarbonylation of (Hetero)Aryl Bromides with a Palladacycle Precatalyst

“…In particular, these substrates are susceptible to S N Ar with the amine nucleophile. 15 Subjecting 2-bromothiazole to the optimized reaction conditions furnished an 86% yield of product 4o , with no observation of product arising from S N Ar. Applying identical conditions on the 2,4-dibromothiazole resulted in only a 73% yield of the desired product 4p .…”

N-(2-Amino-4,6-dihydroxypyrimidin-5-yl)acetamide dihydrate

“…For the biological properties of pyrimidine compounds see: Marchal et al (2010); Giandinoto et al (1996); Sun et al (2006). For related structures, see: Glidewell et al (2003); Nakayama et al (2004); Quesada et al (2004); Hockova et al (2003).…”

“…E67, o2526 Pyrimidine and its derivatives are important targets for drug discovery having attracted much attention for their biological activities and molecular structures (Sun et al, (2006)). Research findings indicate that the pyrimidine derivatives are associated with diverse pharmacological activities, such as antifungal, antibacterial, pesticidal, analgesic, and antitumor (Giandinoto et al;(1996); Nakayama et al, (2004); Hockova et al, (2003)). The present X-ray crystal structure analysis was undertaken in order to study the stereochemistry and crystal packing of the title compound (I).…”