Sulfuric Acid → HCID 10037308, compound

Temperature

100 °C

To a well-stirred mixture consisting of 2-bromo-aniline (5.4 g, 31.4 mmol), sodium 3-nitrobenzene sulfonate (4.25 g, 18.9 mmol), concentrated sulfuric acid (8.5 g, 177 mmol), and water (3.20 ml) heated to 100° C., 2-ethyl acrolein (5.0 ml, 51.06 mmol) was added. After maintaining the reaction temperature at 100° C. for 1 hour, the temperature was increased to 110° C. An additional portion of 2-ethyl acrolein (1.0 ml, 10.2 mmol) was added, and the reaction was stirred at 110° C. for 1 hour. The reaction temperature was then elevated to 120° C. prior to addition of another 1.0 ml (10.2 mmol) portion of 2-ethyl acrolein. After heating the reaction at 120 for 1 hour, the temperature was elevated to 130 prior to addition of 1.0 ml (10.2 mmol) of 2-ethyl acrolein. Finally, the reaction temperature was raised to 140° C. and maintained at that temperature for 2 hours following addition of a final portion (1.3 ml, 13.3 mmol) of 2-ethyl acrolein. The cooled reaction was quenched with ice (60 g), and the pH of the resulting mixture was adjusted to 14 by addition of 6 N aqueous sodium hydroxide. The reaction mixture was then extracted with three 100 ml portions of methylene chloride. The combined organic extracts were dried (anhydrous sodium sulfate) and concentrated in vacuo yielding an amber oil. Flash chromatography of the entire sample (silica gel, 47-61 micron mesh; elution with methylene chloride) afforded the title compound (3.70 g, 50% yield) as an amber oil.

1. temperatureAfter maintaining the reaction temperature at 100° C. for 1 hour
2. temperaturethe temperature was increased to 110° C
3. customwas then elevated to 120° C.
4. temperatureAfter heating
5. customthe reaction at 120 for 1 hour
6. temperatureFinally, the reaction temperature was raised to 140° C.
7. temperaturemaintained at that temperature for 2 hours
8. customThe cooled reaction
9. customwas quenched with ice (60 g)
10. additionthe pH of the resulting mixture was adjusted to 14 by addition of 6 N aqueous sodium hydroxide
11. extractionThe reaction mixture was then extracted with three 100 ml portions of methylene chloride
12. dry with materialThe combined organic extracts were dried (anhydrous sodium sulfate)
13. concentrationconcentrated in vacuo
14. customyielding an amber oil
15. washFlash chromatography of the entire sample (silica gel, 47-61 micron mesh; elution with methylene chloride)

ORD record

ord-103fa7ac394641a080dc82167fa5678d

Source dataset

uspto-grants-2005_05

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US06894062B1