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

A solution of sodium hydroxide (3.35 g, 0.0838 mol) in water (24 mL) is added to a stirred solution of methyl 4-dimethylaminocrotonate (12 g, 0.0838 mol) in methanol (100 mL). The reaction mixture is warmed to 40–45° C. for 1 hour then cooled to room temperature. Hydrochloric acid (5N) is added to bring the pH of the reaction mixture to 1–2. The reaction mixture is concentrated under reduced pressure to a thick oil. Ethanol (anhydrous, 100 mL) is added and the solid (sodium chloride) is removed by filtration. The filtrate is concentrated under reduced pressure and product precipitation is induced by addition of 2-propanol (50 mL) to afford a solid which is collected to give the desired product (7.0 g, 50%). GC-MS purity is 86%. 1HNMR is consistent with expected structure.

1. temperatureThe reaction mixture is warmed to 40–45° C. for 1 hour
2. concentrationThe reaction mixture is concentrated under reduced pressure to a thick oil
3. additionEthanol (anhydrous, 100 mL) is added
4. customthe solid (sodium chloride) is removed by filtration
5. concentrationThe filtrate is concentrated under reduced pressure and product precipitation
6. additionis induced by addition of 2-propanol (50 mL)

ORD record

ord-a9481ea6ea3f4237bf227ec18411e317

Source dataset

uspto-grants-2006_10

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07126025B2