Chemical Properties
Light yellow liquid
Uses
4,4-Diethoxy-N,N-dimethyl-1-butanamine is used in organic synthesis and pharmaceutical intermediates, it is an intermediate for Sumatriptan, Rizatriptan, Almotriptan, Zolmitriptan.
Application
4-Dimethylaminobutyraldehyde Diethyl Acetal (Zolmitriptan USP Related Compound H) is used in the preparation of N,N-Dimethyltryptamines, 5-HT1D receptor agonists, for medicinal treatments such as antimigraine drugs.
Preparation
4-Dimethylaminobutyraldehyde diethyl acetal synthesis: The reaction of 1-bromo-3-chloro propane and dimethylamine solution with PEG as a phase transfer catalyst, and obtained 3-dimethylamino-1-chloro propane. 3-dimethylamino-1-chloro propane reacted with magnesium and Grinard reagent was acquired. 4-Dimethylaminobutyraldehyde diethyl acetal is obtained by the reaction of Grinard reagent and triethyl orthoformate. The yield was 70.11%.
Synthesis
Magnesium shavings (25 g) were added to a 2L four-necked round-bottomed flask under nitrogen protection. Benzene (50 mL), benzene solution of 3-chloro-1-(N,N-dimethyl)propylamine (50 mL), triethyl orthoformate (20 g), and a small amount of iodine crystals were added sequentially and slowly heated to reflux temperature. After 15-20 minutes of refluxing, a vigorous reaction was observed, indicating the onset of the Grignard reaction. The remaining benzene solution of 3-chloro-1-(N,N-dimethyl)propylamine and triethyl orthoformate (174 g, where R3 = R5 = Et) were loaded into two charging funnels and added slowly and dropwise to the reaction mixture over a period of 3-4 hr, maintaining reflux. After completion of the reaction, it was cooled to 25 °C and filtered through a diatomaceous earth pad. The filter cake was washed with benzene (100 mL). Benzene was removed by distillation at atmospheric pressure using a 20 cm Vigreux column. The residue was distilled under mild vacuum with a controlled bath temperature below 100 °C to recover excess triethyl orthoformate (60 g). Finally, 4-dimethylaminobutyraldehyde diethyl acetal was purified by reduced pressure distillation to give 125 g (75.8% yield) of a colorless liquid with a boiling point of 140-150°C/15-20 mmHg.
References
[1] Patent: WO2003/101931, 2003, A2. Location in patent: Page 14-15
[2] Patent: WO2003/101931, 2003, A2. Location in patent: Page 15-16
[3] Patent: WO2004/99141, 2004, A1. Location in patent: Page 9-10
