Preparation of 3-oxo cyclobutane 1-carboxylic acid
Answers
The invention relates to a synthesis method of 3-oxocyclobutanecarboxylic acid. The synthesis method comprises the following concrete steps: (1) adding N,N-dimethyl formamide and potassium tert-butoxide into a flask, stirring, carrying out an ice bath, dropping diisopropyl malonate to be dissolved in DMF, stopping dropping after 3.0 hours, heating and stirring, adding 2,2-dimethoxy-1,3-dibromopropane, stirring and heating to 140 DEG C, keeping the temperature for 4 days, distilling off half of DMF, cooling, adding water, stirring uniformly, adding 1kg of normal heptane, extracting for four times, drying an organic phase, and then carrying out reduced pressure distillation to obtain a product A; and (2) adding the product A obtained in the step (1) into the flask, adding water and concentrated hydrochloric acid while stirring, heating for boiling off 2/3 of solvent, extracting with dichloromethane, drying an organic phase with anhydrous sodium sulfate, then concentrating to obtain a crude product, and re-crystallizing dichloromethane and normal heptane to obtain a final product. The synthesis method provided by the invention has the advantages of few steps, easiness in operation and simple after-treatment, and prepared 3-oxocyclobutanecarboxylic acid has relatively high purity.