Carbon Disulfide → Methyl 3-isothiocyanatopropionate

Temperature

-15 °C

To β-alanine methyl esterhydrochloric acid salt suspended in methylene chloride (60 mL) was added triethylamine (10.87 g, 107.4 mmol). The reaction mixture was cooled downed to -15° C. before adding carbon disulfide (4.1 g, 53.8 mmol) dissolved in chloromethane (30 mL) dropwise over 25 minutes. The reaction was warmed to 10° C. and stirred for 10 minutes. before lowering the temperature to 0° C. and adding ethyl chloroformate (5.83 g, 53.7 mmol) dissolved in chloromethane (5 mL) dropwise over 15 minutes. The temperature was increased to room temperature and stirred for 20 minutes before lowering to 0° C. Triethylamine (5.43 g, 53.7 mmol) was then added. The temperature was increased to room temperature and then stirred for 30 minutes. The reaction mixture was washed with water (50 mL), 1N hydrochloric acid (50 mL), 5% sodium bicarbonate and water (50 mL), dried over magnesium sulfate, filtered and concentrated under vacuo to give 7.3 g. of crude product. Flash chromatography (ethyl acetate/hexane, 1:4) afforded the desired product (4.03 g, 52%).

1. temperatureThe reaction was warmed to 10° C.
2. customto 0° C.
3. temperatureThe temperature was increased to room temperature
4. stirringstirred for 20 minutes
5. custombefore lowering to 0° C
6. temperatureThe temperature was increased to room temperature
7. stirringstirred for 30 minutes
8. washThe reaction mixture was washed with water (50 mL), 1N hydrochloric acid (50 mL), 5% sodium bicarbonate and water (50 mL)
9. dry with materialdried over magnesium sulfate
10. filtrationfiltered
11. concentrationconcentrated under vacuo
12. customto give 7.3 g

ORD record

ord-b9ea9754a6d44cd6860900220b869f89

Source dataset

uspto-grants-1998_04

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US05741804