Hydrochloric Acid → 2-Amino-5-methoxytetralin

HRID 1380864Notes

Reaction equation

HRID 1380864 reaction equation
[CH3:1][O:2][C:3]1[CH:12]=[CH:11][CH:10]=[C:9]2[C:4]=1[CH2:5][CH2:6][C:7](=O)[CH2:8]2.C([O-])(=O)C.[NH4+].C([BH3-])#[N:20].[Na+].Cl>CO.ClCCCl>[NH2:20][CH:7]1[CH2:6][CH2:5][C:4]2[C:9](=[CH:10][CH:11]=[CH:12][C:3]=2[O:2][CH3:1])[CH2:8]1

Participants

7

Reactant 4

HCID 313Hydrochloric AcidHCID 2591945-Methoxy-2-tetraloneHCID 517165Ammonium AcetateHCID 5003444Sodium cyanoborohydride

Product 1

HCID 114693952-Amino-5-methoxytetralin

Reagents, catalysts & solvents 2

HCID 111,2-DichloroethaneSolventHCID 887MethanolSolvent

Procedure

First, 5-methoxy-1,2,3,4-tetrahydronaphthalen-2-one (17.6 g, 0.1 mol) is dissolved in methanol (800 ml) and 1,2-dichloroethane (200 ml), then it is mixed with ammonium acetate (77 g) and sodium cyanoborohydride (5.4 g) and stirred for 2 days at laboratory temperature. The reaction mixture is adjusted to pH 2 with concentrated hydrochloric acid and the solvent is distilled off in vacuo. The residue is dissolved in ethyl acetate/water. The aqueous phase is separated off, made alkaline with 50% sodium hydroxide solution with cooling and extracted twice with methylene chloride. The extract is dried, treated with Fuller's earth/activated charcoal and concentrated by evaporation. The residue is dissolved in acetone and the hydrochloride is precipitated with ethereal hydrochloric acid. Yield: 2 g. Mp: 260°-262° C. (decomp.).

Workup

  1. distillationthe solvent is distilled off in vacuo
  2. dissolutionThe residue is dissolved in ethyl acetate/water
  3. customThe aqueous phase is separated off
  4. temperaturewith cooling
  5. extractionextracted twice with methylene chloride
  6. customThe extract is dried
  7. additiontreated with Fuller's earth/activated charcoal
  8. concentrationconcentrated by evaporation
  9. dissolutionThe residue is dissolved in acetone
  10. customthe hydrochloride is precipitated with ethereal hydrochloric acid

Sources & evidence

ORD record
ord-fd541bf2ffff4e4b9aab0788f61ddc27
Source dataset
uspto-grants-1986_04
Patent number
US04584293

Reaction notes

Loading…