Synthesis
In a 250mL three-necked flask equipped with a stirrer and a dropping funnel, 16.2g of sodium hydroxide and 40mL of distilled water were added, dissolved with uniform stirring, and cooled to 5C with cold water. Add 15.7g of bromine under constant stirring and continue stirring for 20min after addition to fully react the bromine to obtain a mixed NaOH-NaOBr solution. Keeping the temperature low and stirring evenly, 4-aminobenzamide synthesized in the previous step was dissolved in 50 mL of distilled water, and the 4-aminobenzamide solution was added dropwise gradually. After the dropwise addition was completed, the rearrangement reaction was carried out, and the reaction temperature was controlled at 30 , and the reaction was maintained for 30 min. then the temperature was slowly increased, and the reaction temperature was controlled at about 85 , and the reaction was continued for 35 min. Cooling and pumping were performed, and the filtrate was extracted with ether, and dried in vacuo to obtain 10.4 g of p-phenylenediamine, with a yield of 97.6% and a purity of 99.6%.
To a solution of dichloromethane of p-phenylenediamine was added triethylamine, and a dropwise addition of triethylamine. Add triethylamine to the dichloromethane solution of p-phenylenediamine, add dichloromethane solution of di-tert-butyl dicarbonate dropwise, dropwise, react for 15 hours, evaporate the solvent under reduced pressure, and the concentrate was purified by silica gel column chromatography [eluent: V (ethyl acetate)/V (petroleum ether)=1/10] to obtain the compound specific base carbamylate lipase.
