Preparation method of 3-(2-chloro-1-oxopropyl)-spiro[2H-1,3-benzoxazine-2,1'-cyclohexan]-4(3H)-one as meropenem intermediate

The invention provides a preparation method of 3-(2-chloro-1-oxopropyl)-spiro[2H-1,3-benzoxazine-2,1'-cyclohexan]-4(3H)-one as a meropenem intermediate. According to the preparation method, alpha-chloropropionyl chloride with lower reaction activity is adopted and cooperates with specific raw materials to play a role together, so that the reaction yield is greatly increased instead of being reduced; meanwhile, due to the lower activity of alpha-chloropropionyl chloride, fewer side reactions participate in the reaction, an obtained product contains fewer impurities, and 3-(2-chloro-1-oxopropyl)-spiro[2H-1,3-benzoxazine-2,1'-cyclohexan]-4(3H)-one with higher yield and purity is obtained and can replace 3-(2-bromo-1-oxopropyl)-spiro[2H-1,3-benzoxazine-2,1'-cyclohexan]-4(3H)-one for preparing meropenem. Besides, a synthetic process of 3-(2-chloro-1-oxopropyl)-spiro[2H-1,3-benzoxazine-2,1'-cyclohexan]-4(3H)-one requires no magnetic solid base catalysts, so that the reaction conditions are safer, the reaction path