反应详情

温度

0 °C

1000 mL of IPA was placed in a 3 L flask and cooled to 0° C. A steady stream of methylamine gas from a cylinder was slowly passed through the IPA until the total volume reached 1750 ml. 100 g of (2-[4-hydroxyphenyl]ethyl) bromide (A11) was added to the cooled methylamine IPA solution in several portions. The cooling bath was removed after all A11 was added. The reaction mixture was allow to warm to room temperature and continue to stir for another 10-12 h. The excess methylamine was distilled into another 1000 mL of pre-cooled to 0° C. IPA by heating the reaction mixture at 50° C. When most of the methylamine was distilled off, the bath temperature was raised to 100° C. and the IPA was distilled out. After most of the IPA had been distilled out, about 300 mL of IPA was added to the reaction mixture and distillation was continued to aid removal of the methylamine. After the volume was reduced to 250 mL, the reaction mixture was allowed to cool down to room temperature. The precipitate was collected by filtration and washed by toluene to give 104 g (90% yield) of N-methyl-N-(2-[4-hydroxyphenyl]ethyl) amine as an HBr salt (A12 HBr). 1H NMR (CDCl3) δ 2.69 (3H, s, CH3), 2.90 (2H, t, J=7.2 Hz), 3.18 (2H, t, J=6.3 Hz), 6.76 (2H, d, J=8.7 Hz), 7.11 (2H, d, J=8.7 Hz)

1. customThe cooling bath was removed after all A11
2. additionwas added
3. temperatureto warm to room temperature
4. distillationThe excess methylamine was distilled into another 1000 mL
5. temperatureof pre-cooled to 0° C
6. temperatureIPA by heating the reaction mixture at 50° C
7. distillationWhen most of the methylamine was distilled off
8. temperaturethe bath temperature was raised to 100° C.
9. distillationthe IPA was distilled out
10. distillationAfter most of the IPA had been distilled out
11. additionabout 300 mL of IPA was added to the reaction mixture and distillation
12. customremoval of the methylamine
13. temperatureto cool down to room temperature
14. filtrationThe precipitate was collected by filtration
15. washwashed by toluene