Acetonitrile → 4-(Dimethylamino)-2-butenoyl chloride hydrochloride

A 1 L multi-neck flask equipped with agitator, thermometer, addition funnel, and nitrogen protection is charged with acetonitrile (0.67 kg, 0.85 L) followed by adding dimethylformamide (0.00086 kg, 0.91 mL, d=0.944 g/mL). At ambient temperature, is added 4-dimethylaminocrotonic acid hydrochloride (0.0709 kg) and the mixture stirred until homogeneous. Cool the reaction mixture to (0–10° C.) and add oxalyl chloride (0.0473 kg, 0.0325 L, d=1.45 g/mL) dropwise over (20 minutes) at (0–10° C.) followed by a rinse with acetonitrile (0.02 kg, 0.03 L). The temperature (0–10° C.) is maintained for about (20 minutes). The temperature of the reaction mixture is adjusted to (22–26° C.) over (20 minutes) and maintained over (2 hours). The temperature of reaction mixture is adjusted to (40–45° C.) and held for about (5 minutes). Cool the light suspension to about (20–25° C.) and check for reaction completion by high-pressure liquid chromatography (HPLC). The reaction is complete when there is ≦15% of the starting material (4-dimethylaminocrotonic acid hydrochloride) present and/or ≦2% of oxalyl chloride (detected as the dimethyl oxalate).

1. customA 1 L multi-neck flask equipped with agitator
2. additionthermometer, addition funnel
3. temperatureCool the reaction mixture to (0–10° C.)
4. washa rinse with acetonitrile (0.02 kg, 0.03 L)
5. temperatureThe temperature (0–10° C.) is maintained for about (20 minutes)
6. customis adjusted to (22–26° C.) over (20 minutes)
7. temperaturemaintained over (2 hours)
8. customThe temperature of reaction mixture
9. customis adjusted to (40–45° C.)
10. customheld for about (5 minutes)
11. temperatureCool the light suspension to about (20–25° C.)
12. customcheck for reaction completion by high-pressure liquid chromatography (HPLC)

ORD record

ord-74ac10285c504dd6b77f3cf8821bc883

Source dataset

uspto-grants-2006_10

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07126025B2