Weighed 12ml of carbon disulfide dissolved in 100ml of methanol, slowly added N,N'-dimethylpropylenediamine 20.4g dropwise, control the temperature at 10-15 C, dropwise process of white solid generation, dropwise completion of the 10-15 C heat preservation for 1 hour, filtration, methanol foam wash to obtain a white solid 38g (Intermediate 1), yield 95%.
Weighing the product of the previous step 38g, add 120ml chloroform, control the temperature at 10-15 , add triethylamine 24.2g, and then slowly add 11.1g ethyl chloroformate dropwise, dropwise for 1 hour, dropwise completion of the holding time of 1 hour, to dissolve the clear, wash the organic phase, filtration, drying to get the product (Intermediate 2).
Weighed 12.9g of ethylamine (containing 70% water), added 60ml of chloroform, cooled down to 10-15 C, slowly dropwise addition of intermediate 2, dropwise addition is completed holding for 1 hour, wash the organic phase with pH = 11-12 alkaline solution, drying, depressurization, concentration, to obtain 31.6g of oil, (intermediate 3), add 0.012g of TEABA, 25 C, with a mass of Concentration of 10% sodium hypochlorite 270g for oxidation, oxidation is complete, extraction and layering, the organic phase is dried and concentrated at 30 under reduced pressure, the solvent is evaporated and dried, and then distilled under reduced pressure to obtain EDC 25g, purity 99.2%;
Weighing 39g of triethylamine hydrochloride, add 100ml of dichloromethane, controlled at 30 , slowly dropwise addition of EDC obtained from the distillation, the first dissolution of the clear and then Dialysis of crystals, dropwise addition is completed, lower the temperature to 5 , dialysis of crystals 1h, filtration, to obtain 30.56g 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride, purity 99.5%, yield 80.4% (to N,N'-dimethylpropylenediamine).
