Acetone → (R)-3-(N-Isopropylamino)-5-methoxychroman

HRID 37679

Reaction equation

HRID 37679 reaction equation
[NH2:1][C@@H:2]1[CH2:11][C:10]2[C:5](=[CH:6][CH:7]=[CH:8][C:9]=2[O:12][CH3:13])[O:4][CH2:3]1.[CH3:14][C:15]([CH3:17])=O.[BH3-]C#N.[Na+]>C(O)(=O)C.CO>[CH:15]([NH:1][C@@H:2]1[CH2:11][C:10]2[C:5](=[CH:6][CH:7]=[CH:8][C:9]=2[O:12][CH3:13])[O:4][CH2:3]1)([CH3:17])[CH3:14]

Participants

6

Reactant 3

HCID 180AcetoneHCID 5003444Sodium cyanoborohydrideHCID 10845076(R)-5-methoxychroman-3-amine

Product 1

HCID 10489181(R)-3-(N-Isopropylamino)-5-methoxychroman

Reagents, catalysts & solvents 2

HCID 176Acetic AcidSolvent2×HCID 887MethanolSolvent

Procedure

(R)-3-Amino-5-methoxychroman (1.0 g; 6mmol) and acetone (2.5 g; 40 mmol) were mixed with methanol (820 ml), acetic acid (0.4 g; 6.6 mmol) and NaCNBH3 (1.2 g; 19 mmol), pH was adjusted to 6.0 with acetic acid. Stirring was continued at room temperature for 3 days. The mixture was evaporated and the residue was made alkaline and extracted with CH2Cl2. After drying (Na2SO4) and evaporation the title compound as base was transformed to the HCl-salt. Yield: 1.1 g (83%). Mp: 289° dec. [α]D25 =-29° (C=0.015; MeOH)

Workup

  1. customThe mixture was evaporated
  2. extractionextracted with CH2Cl2
  3. customAfter drying
  4. custom(Na2SO4) and evaporation the title compound as base
  5. customMp: 289° dec. [α]D25 =-29° (C=0.015; MeOH)

Sources & evidence

ORD record
ord-357e907a4aeb4e348d7d9c7ecfbd720e
Source dataset
uspto-grants-1995_05
Patent number
US05420151

Linked notes

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