19844-94-1

Upstream product

• 19844-93-0 3-Benzylxanthine 
• 5770-23-0 6-amino-5-nitroso-1-(phenylmethyl)-2,4(1H,3H)-pyrimidinedione 
• 172751-17-6 5,6-diamino-1-(phenylmethyl)-2,4(1H,3H)-pyrimidinedione 
• 41862-11-7 1-benzyl-6-aminouracil 

Relevant academic research and scientific papers

Imidazo[2,1-i]purin-5-ones and related tricyclic water-soluble purine derivatives: Potent A2A- and A3-adenosine receptor antagonistst

A series of tricyclic imidazo[2,1-i]purinones and ring-enlarged analogues derived from xanthine derivatives have been prepared as adenosine receptor (AR) antagonists. In comparison with xanthines, the tricyclic compounds exhibit increased water solubility due to a basic nitrogen atom, which can be protonated under physiological conditions. Substituents were introduced that confer high affinity for A2A or A3 ARs, respectively. A new capillary electrophoresis method was developed for the determination of the enantiomeric purity of selected chiral products using native and modified β-cyclodextrins as chiral discriminators. The compounds were investigated in radioligand binding assays at rat brain A1 and A2A ARs. Selected compounds were additionally investigated in radioligand binding assays at human recombinant A3 ARS and in functional studies (adenylate cyclase assays) at A1 ARs of rat fat cell membranes, A2A ARs of rat PC 12 cell membranes, and mouse A2B ARs of NIH 3T3 cell membranes. Structure-activity relationships were similar to those of corresponding xanthine derivatives. The 2-styrylimidazopurinones were less potent at A2A ARs as compared to 8-styrylxanthine derivatives. The most potent compound at A2A ARs was (S)-1,4-dimethyl-8-ethyl-2-styryl- imidazo[2,1-i]purinone (S-25) exhibiting a Ki value of 424 nM at rat A2A ARs. The compound was highly selective for A2A receptors vs A1 and A3 ARs. Selectivity vs A2B ARs, however, was low. Among the 1-unsubstituted 2-phenyl-imidazo[2,1-i]purin-5-one derivatives, very potent and highly selective antagonists for human A3 ARs were identified. The most potent A3 antagonist of the present series was (R)-4-methyl-8-ethyl-2-phenyl-imidazo[2,1-i]purin-5-one (R-24) exhibiting a Ki value of 2.3 nM and high selectivity for A3 receptors vs all other AR subtypes.

Condensed purine derivatives

There are disclosed condensed purine derivatives represented by formula; STR1 in which R3 represents hydrogen, lower alkyl or benzyl; each of X1 and X2 independently represents hydrogen, lower alkyl, aralkyl or phenyl; and

s-Triazolo(3,4-I)purine derivatives

There are disclosed s-triazolo[3,4-i]purine derivatives represented by formula: STR1 wherein Y-Z represents STR2 R4 represents hydrogen, alkyl, substituted or unsubstituted aromatic heterocyclic group or substituted or unsubstituted aryl; and X2 represents oxygen, sulfur or NH; each of R1 and R2 independently represents hydrogen, alkyl, cycloalkyl, aralkyl or substituted or unsubstituted aryl; R3 represents alkyl, cycloalkyl, aralkyl or substituted or unsubstituted aryl; X1 represents oxygen or sulfur; and represents a single bond or a double bond or pharmaceutically acceptable salts thereof.