[{"from": "human", "value": "Could you give me a brief overview of this molecule? [C][C][=C][Branch1][=Branch1][C][=N][O][Ring1][Branch1][C][=Branch1][C][=O][N][C][=C][C][=C][Branch1][Branch1][C][=C][Ring1][=Branch1][C][Branch1][C][F][Branch1][C][F][F]"}, {"from": "gpt", "value": "The molecule is a pyrimidine synthesis inhibitor belonging to the DMARD (disease-modifying antirheumatic drug) class of drugs, which are chemically and pharmacologically very heterogeneous. Leflunomide was approved by FDA and in many other countries (e.g., Canada, Europe) in 1999."}]