[{"from": "human", "value": "Generate a molecule based on this description. The molecule is a Purine Antimetabolite. The mechanism of action of azathioprine is as a Nucleic Acid Synthesis Inhibitor."}, {"from": "gpt", "value": "[C][N][C][=N][C][=Branch2][Ring1][C][=C][Ring1][Branch1][S][C][=N][C][=N][C][=C][Ring1][=Branch1][N][C][=N][Ring1][Branch1][N+1][=Branch1][C][=O][O-1]"}]