Crystal form a of brivaracetam intermediate and preparation method thereof, and crystal form c of brivaracetam and preparation method thereof

Disclosed are a novel crystal form of a brivaracetam intermediate compound (I) and preparation method thereof, and a novel crystal form of brivaracetam and preparation method thereof, specifically a crystal form A of a compound I and a crystal form C of brivaracetam. The crystal form A provided in the present invention has beneficial properties such as good stability, technologically developable property, and easy-to-treat property; moreover, the crystal form A features a simple preparation method and low costs, and is significantly valuable for the production, the purification, and the quality control of active ingredients of the drug. The crystal form C provided in the present invention has beneficial properties such as good stability, technologically developable property, and easy-to-treat property; moreover, the crystal form A features a simple preparation method and low costs, and is significantly valuable for future optimization and development of the drug.