[{"from": "human", "value": "Based on the given information, design a molecule that meets the desired specifications. The molecule is an Alkylating Drug. The mechanism of action of busulfan is as an Alkylating Activity."}, {"from": "gpt", "value": "[C][S][=Branch1][C][=O][=Branch1][C][=O][O][C][C][C][C][O][S][=Branch1][C][=O][=Branch1][C][=O][C]"}]