合成路线1

A new synthesis of A-515-U has been reported. The compound can be synthesized in two similar ways: 1) The reaction of 9-(2-acetoxyethoxymethyl)-2-(acetylamino)-6,9-dihydro-1H-purin-6-one (I) with POCl3 and 2,4,6-trimethylpyridine in refluxing acetonitrile gives 9-(2-acetoxyethoxymethyl)-2-(acetylamino)-6-chloro-9H-purine (II), which is dechlorinated with formic acid - triethylamine and Pd/C in refluxing acetone, yielding 9-(2-acetoxyethoxymethyl)-2-(acetylamino)-9H-purine (III). Finally, this compound is deacetylated in water. 2) Purine (I) is partially deacetylated with triethylamine in refluxing ethanol to give 9-(2-acetoxyethoxymethyl)-2-amino-6,9-dihydro-1H-purin-6-one (IV), which is treated with POCl3 as before to yield the chloropurine (V). The dechlorination of (V) with HCO2H as before or with ammonium formate - Pd/C affords 9-(2-acetoxyethoxymethyl)-2-amino-9H-purine (VI), which is finally deacetylated with methylamine as before.