n-(3-dimethylaminopropyl)-n'-ethylcarbodiimide hydrochloride

Description

Among the carbodiimides available, n-(3-dimethylaminopropyl)-n'-ethylcarbodiimide (EDC) hydrochlorideis commonly used because it is available as an HCl salt, is easy to handle, and the urea by-product, N-(3-dimethylaminopropyl)-N' -ethylurea (EDU), is soluble in water and can easily be removed[1].

Uses

N-(3-Dimethylaminopropyl)-N'-ethylcarbodiimide (EDC) is a carbodiimide coupling reagent commonly used for the preparation of amides from carboxylic acids and amines[1].

Toxicology

N-(3-dimethylaminopropyl)-N'-ethylcarbodiimide hydrochloride (EDC) was considered to be potentially genotoxic; however, later studies determined that EDC is not genotoxic. 4 in vitro Ames bacterial mutagenicity tests indicated EDC is genotoxic, but the reagent is not genotoxic in vivo when administered to rats orally. When administered orally, EDC is hydrolyzed to EDU, which is not genotoxic[1].

Synthesis

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).

References

[1] Kai Cao, Samuel J. Bonacorsi Jr, John A. Brailsford. “Synthesis of stable-isotope-labeled N-(3-dimethylaminopropyl)-N′-ethylcarbodiimide and N-(3-dimethylaminopropyl)-N′-ethylurea.” Journal of labelled compounds & radiopharmaceuticals 63 13 (2020): 526–530.