Acetic Acid → (R)-(-)-N-acetyl-7,8-dimethoxy-4-(3,4-dimethoxyphenyl)-1,2,3,4-tetrahydroisoquinoline

HRID 54687Notes

Reaction equation

HRID 54687 reaction equation
[CH3:1][O:2][C:3]1[C:12]([O:13][CH3:14])=[C:11]2[C:6]([C@@H:7]([C:15]3[CH:20]=[CH:19][C:18]([O:21][CH3:22])=[C:17]([O:23][CH3:24])[CH:16]=3)[CH2:8][NH:9][CH2:10]2)=[CH:5][CH:4]=1.[C:25](O)(=[O:27])[CH3:26]>ClCCl>[C:25]([N:9]1[CH2:8][C@H:7]([C:15]2[CH:20]=[CH:19][C:18]([O:21][CH3:22])=[C:17]([O:23][CH3:24])[CH:16]=2)[C:6]2[C:11](=[C:12]([O:13][CH3:14])[C:3]([O:2][CH3:1])=[CH:4][CH:5]=2)[CH2:10]1)(=[O:27])[CH3:26]

Participants

4

Reactant 2

HCID 176Acetic AcidHCID 53962959(R)-(+)-7,8-dimethoxy-4-(3,4-dimethoxyphenyl)-1,2,3,4-tetrahydroisoquinoline

Product 1

HCID 54226046(R)-(-)-N-acetyl-7,8-dimethoxy-4-(3,4-dimethoxyphenyl)-1,2,3,4-tetrahydroisoquinoline

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent

Procedure

(i) 2.0 g of (R)-(+)-7,8-dimethoxy-4-(3,4-dimethoxyphenyl)-1,2,3,4-tetrahydroisoquinoline was dissolved in 10 ml of dichloromethane; after adding 0.86 ml of anhydrous acetic acid thereto at room temperature, the mixture was allowed to react for 30 minutes. The reaction solution was concentrated and subjected twice to azeotropic distillation with toluene. Then dichloromethane was added and the mixture was basified by adding 1N aqueous sodium hydroxide. After separation, the dichloromethane layer was washed with water and dried over anhydrous magnesium sulfate. The solvent was distilled off, and the resulting residue was recrystallized from ethylacetate-n-hexane, affording 2.12 g of (R)-(-)-N-acetyl-7,8-dimethoxy-4-(3,4-dimethoxyphenyl)-1,2,3,4-tetrahydroisoquinoline. m.p. 128° C.; [α]D20 =-39° (C=1, CHCl3).

Workup

  1. customat room temperature
  2. customto react for 30 minutes
  3. concentrationThe reaction solution was concentrated
  4. distillationsubjected twice to azeotropic distillation with toluene
  5. additionThen dichloromethane was added
  6. additionby adding 1N aqueous sodium hydroxide
  7. customAfter separation
  8. washthe dichloromethane layer was washed with water
  9. dry with materialdried over anhydrous magnesium sulfate
  10. distillationThe solvent was distilled off
  11. customthe resulting residue was recrystallized from ethylacetate-n-hexane

Sources & evidence

ORD record
ord-f19cac144bea44feb44c5fb0429ea15b
Source dataset
uspto-grants-1997_04
Patent number
US05623074

Reaction notes

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