17495-10-2

Upstream product

• 17495-12-4 2-amino-7-benzyl-1H-purin-6(7H)-one 
• 108-24-7 acetic anhydride 
• 73-40-5 2-amino-1,9-dihydro-6H-purin-6-one 
• 100-39-0 benzyl bromide 
• 6979-94-8 2',3',5'-tri-O-acetyl-guanosine 
• 118-00-3 G 
• 100-44-7 benzyl chloride 

Downstream Products

• 204515-22-0 2-acetyl-7-benzyl-9-[(2,2-dimethyl-4,6-dioxo-1,3-dioxan-5-yl)ethyl]guaninium inner salt 
• 81777-40-4 2-acetoxyethoxymethyl bromide 
• 33147-25-0 2-[2-(guanin-9-yl)ethyl]butanoic acid 
• 39809-25-1 Penciclovir 
• 59278-00-1 2-acetoxyethyl acetoxymethyl ether 
• 256945-19-4 9-[4-acetoxy-3-(acetoxymethyl)but-1-yl]-2-acetylamino-6-(2',4',6'-triisopropylbenzenesulfonyloxy)-9H-purine 
• 256945-24-1 7-(4-acetoxybut-1-yl)-2-acetylamino-6-(2',4',6'-triisopropylbenzenesulfonyloxy)-7H-purine 
• 794497-80-6 5-[2-(N²-acetyl-9-benzylguanin-7-yl)ethyl]-2,2-dimethyl-1,3-dioxacyclohexane-4,6-dione 
• 104227-86-3 6-deoxypenciclovir 
• 127205-22-5 7-[4-hydroxy-3-(hydroxymethyl)but-1-yl]guanine 
• 104227-87-4 9-(4-acetoxy-3-acetoxymethylbutyl)-2-aminopurine 
• 14937-72-5 9-benzylguanine 
• 17495-11-3 N²-acetyl-9-benzylguanine 
• 17495-12-4 2-amino-7-benzyl-1H-purin-6(7H)-one 

Relevant academic research and scientific papers

Practical syntheses of penciclovir and famciclovir from N2-acetyl-7-benzylguanine

We have established practical methods for the synthesis of penciclovir (PCV) and famciclovir (FCV) from readily available guanosine via N2-acetyl-7-benzylguanine. The alkylation of N2-acetyl-7-benzylguanine proceeded selectively at the N9 position to give the desired alkylated product in good yield in salt form. After conventional catalytic hydrogenolysis of the benzyl group and hydrolysis of the resulting acetate, pure PCV was obtained without the need for chromatography. As a side chain precursor, the mesylate was selected rather than a halide since the corresponding halides gave several impurities under the same reaction conditions. Two procedures for the synthesis of FCV from PCV and a derivative are also reported.

Regioselective functionalization of guanine: Simple and practical synthesis of 7- and 9-alkylated guanines starting from guanosine

Reaction of N2-acetyl-9- and/or -7-benzylated guanines 8 and 12 with selected alkylating agents in 1-methyl-2-pyrrolidone at 120°C yielded the guaninium salts 9 and 13. The salts were consequently transformed by phase transfer hydrogenation into N7- and N9-isomers 10 and 14, respectively, in a highly regioselective manner. A convenient deoxygenation of both derivatives, achieved via the corresponding O6-arenesulfonates, into 2-aminopurine potential prodrugs was also established.

Process for producing purine derivatives

A process for preparing 7-benzylpurine derivatives is provided. An acetylpurine nucleoside is reacted with a benzyl halide to benzylate the 7-position of the purine base, and an acid is then added to the reaction mixture to hydrolyze the glycoside bond. The 7-benzylpurines may be used to prepare 9-substituted purine derivatives.

Process for producing purine derivatives

Purine derivatives in which a desired substituent is introduced into the 9-position only are synthesized by first introducing an easily-removable substituent in the 7-position of a purine base of natural purine nucleosides obtained through fermentation or derivatives thereof, then hydrolyzing the ribose moiety to form purine derivatives having the substituent in the 7-position, subsequently introducing the desired substituent in the 9-position, and then removing the substituent in the 7-position.