Synthesis Of7-amino-5-hydroxy-6-aryiazo-pyrazolo[1,5-a]pyrimidine-3-carboxylic Acid Ethyl Ester

Objective: Basic groups as an indispensable structure appeared inbiological synthesis of DNA or RNA. Therefore, it is a method to researchanti-cancer drugs that changing the structure of basic groups in the nucleicacid, which can restrain on the metabolic way of tumor cell, especially on liveand reproduce of tumor cell. In this subject, we designed and synthesized a seriesof purine base analogues with bioisoterism, expecting to find lead compoundsthat have anti-cancer effects by screening them. Methods: Ethylcyanoacetatereacted with triethyl orthoformate to synthesize intermediateethylethoxymethylenecyanoacetate.The condensing agent is acetic anhydride.And ethyl3(5)-aminopyrazole-4-carboxylate（2）were synthesized by the reactionof ethylethoxymethylenecyanoacetate and hydrazinehydrate with alcohol underreflux. Ethylcyanoacetate reacted with2, cyclized to give the keyintermediate7-amino-5-hydroxypyrazolo[1,5-a]pyrimidine-3-carboxylate（3）.Through diazotization and coupling, the objective compounds7-amino-5-hydroxy-6-arylazopyrazolo[1,5-a]pyrimidine-3-carboxylate derivatives weresynthesized. The structures of these compounds were identified by thecomprehensive methods of TLC, LC-MS,1H-NMR, IR, and elemental analysis. Result:Thirteen new purine analogues were synthesized. Conclusion: The resultingcompounds were all identical to the objective compounds by spectroscopicmethods.The pharmacological test for these compounds is being carried out.