Hydrogen Bromide → N-Methyltyramine

HRID 1015918Notes

Reaction equation

HRID 1015918 reaction equation
[CH3:1][NH2:2].[OH:3][C:4]1[CH:9]=[CH:8][C:7]([CH2:10][CH2:11]Br)=[CH:6][CH:5]=1.CN.CC(O)C.Br>CC(O)C>[CH3:1][NH:2][CH2:11][CH2:10][C:7]1[CH:8]=[CH:9][C:4]([OH:3])=[CH:5][CH:6]=1

Participants

6

Reactant 4

HCID 260Hydrogen BromideHCID 6329MethylamineHCID 842214-(2-Bromoethyl)phenolHCID 19903027HCID 19903027, compound

Product 1

HCID 9727N-MethyltyramineYield 90%

Reagents, catalysts & solvents 1

HCID 3776IsopropanolSolvent2×

Conditions

Temperature
0 °C

Procedure

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)

Workup

  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

Sources & evidence

ORD record
ord-3c5c745791a944d39da6234b8f57a45e
Source dataset
uspto-grants-2011_07
Patent number
US07985879B2

Reaction notes

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