Hydrochloric Acid → (2E)-4-(Dimethylamino)-2-butenoic acid hydrochloride

Temperature

45 °C

(E)-ethyl 4-(dimethylamino)but-2-enoate hydrochloride (20 g, 0.103 mol) was dissolved in water (102 mL) in 250 mL two-neck flask, and then conc. HCl (2.6 mL) was added therein. After refluxing the reaction mixture for 3 hours, the temperature of the reaction mixture was reduced to room temperature. EtOH formed in the reaction was eliminated by distillation under reduced pressure, and then water (34 mL) was added therein. After adding conc. HCl (1.3 mL) therein again, the reaction mixture was refluxed again for 2 hours and water in the reaction mixture was eliminated by distillation under reduced pressure. Re-crystallization was carried out by adding IPA (100 mL) to the solid remained therein. At this time, IPA solution was heated to the temperature of 40 to 50° C., and the solution was stirred for 2 hours at room temperature. After filtering the solid with a filter, the solid was washed with IPA (10 mL). (E)-4-(dimethylamino) but-2-enoic acid hydrochloride of 12 g was obtained with a yield of 70% by drying the collected solid (99.8% Purity by HPLC, Corona Detector).

1. temperatureAfter refluxing the reaction mixture for 3 hours
2. customwas reduced to room temperature
3. distillationwas eliminated by distillation under reduced pressure
4. additionwater (34 mL) was added
5. additionAfter adding conc. HCl (1.3 mL)
6. temperatureagain, the reaction mixture was refluxed again for 2 hours
7. distillationwater in the reaction mixture was eliminated by distillation under reduced pressure
8. additionby adding IPA (100 mL) to the solid
9. filtrationAfter filtering the solid with a filter
10. washthe solid was washed with IPA (10 mL)

ORD record

ord-a79ecad9147f43f6b3e50f944b4ea2a7

Source dataset

uspto-grants-2014_07

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08779192B2