反应详情

温度

70 °C

Phosgene (50 mmol of a 20% w/w solution in toluene) was added to N,N-dimethylformamide (3.9 mL, 50 mmol) with stirring in an ice bath over 5 min to give a white paste. This mixture was allowed to stand until no further gas evolution was observed (˜30 min). Methyl 7,7-dimethoxyheptanoate (5.1 g, 25 mmol), prepared from cycloheptene following a published method (Claus, R. E., and Schreiber, S. L. (1986) Ozonolytic cleavage of cyclohexene to terminally differentiated products: methyl 6-oxohexanoate, 6,6-dimethoxyhexanal, methyl 6,6-dimethoxyhexanoate. Organic Syntheses 64, 150-156.), was then added dropwise to the reaction solution followed by heating at 70° C. for 1 hour. After cooling, the solvent was removed by rotary evaporation giving a yellow-brown oil. The oil was suspended in water (20 mL) then 5 mL of 10% aqueous HCl and aniline hydrochloride (6.5 g, 50 mmol) were added. The resulting mixture was sealed in a thick-walled glass pressure tube and heated at 120° C. in an oil bath for 1.5 hours. After heating, the reaction solution was cooled slowly to room temperature over 2 hours, during which the product crystallized (if the reaction is cooled too quickly, a sticky precipitate is formed instead). After filtration and washing with water, 1 is obtained as a yellow solid (2.05 g, 23%). 1H NMR (400 MHz, DMSO-d6): δ 8.72 (d, 2H, J=12 Hz), 7.58 (d, 4H, J=8.4 Hz), 7.51 (t, 4H, J=8.0 Hz), 7.30 (t, 4H, J=7.2 Hz), 2.77 (t, 2H, J=6.4 Hz), 2.27 (t, 2H, J=7.6 Hz), 1.71-1.64 (m, 2H), 1.50-1.42 (m, 2H). HRMS-ESI [M]+ m/z calcd. for [C20H23N2O2]+ 323.1754, found 323.1743.

1. customto give a white paste
2. custom(˜30 min)
3. addition), was then added dropwise to the reaction solution
4. temperatureAfter cooling
5. customthe solvent was removed by rotary evaporation
6. customgiving a yellow-brown oil
7. customThe resulting mixture was sealed in a thick-walled glass pressure tube
8. temperatureheated at 120° C. in an oil bath for 1.5 hours
9. temperatureAfter heating
10. temperaturethe reaction solution was cooled slowly to room temperature over 2 hours, during which the product
11. customcrystallized (if the reaction
12. temperatureis cooled too quickly
13. customa sticky precipitate is formed instead)
14. filtrationAfter filtration
15. washwashing with water