6-Chloropurine is one of the main intermediates in the synthesis of adenine, which is obtained by ammoniation at the 6-position. Adenine, chemical name 6-aminopurine, its derivatives are widely used in medicine and agrochemicals and other fields. For example, it is the main raw material for the synthesis of vitamin B4 (adenine phosphate); Adefovirdi-pivoxil (9-[2-[bis(t-valeryloxymethoxy)phosphonomethoxy]ethyl]adenine developed by Gileadsciences Chemicalbook in the United States, approved by the FDA in September 2002, has become a new drug of nucleoside analogues for the treatment of hepatitis B, which can effectively inhibit the replication of hepatitis B virus DNA strands after oral administration.