Sodium cyanoborohydride → 1,2,3,5,6,10b-Hexahydropyrrolo[2,1-a]isoquinoline

HRID 369971Notes

Reaction equation

HRID 369971 reaction equation
[Cl-].[CH2:2]1[C:6]2[C:7]3[C:12]([CH2:13][CH2:14][N+:5]=2[CH2:4][CH2:3]1)=[CH:11][CH:10]=[CH:9][CH:8]=3.C1(CCNC(=O)CCCCl)C=CC=CC=1.C(O)(C)C.ClCCl.C([BH3-])#N.[Na+]>CO.C(O)(=O)C>[CH2:2]1[CH:6]2[C:7]3[C:12]([CH2:13][CH2:14][N:5]2[CH2:4][CH2:3]1)=[CH:11][CH:10]=[CH:9][CH:8]=3

Participants

7

Reactant 4

HCID 5003444Sodium cyanoborohydrideHCID 51423824-chloro-N-(2-phenylethyl)butanamideHCID 215842712,3,5,6-tetrahydro-1H-pyrrolo[2,1-a]isoquinolinium chlorideHCID 21966342Isopropanol methylene chloride

Product 1

HCID 122723731,2,3,5,6,10b-Hexahydropyrrolo[2,1-a]isoquinolineYield 70%

Reagents, catalysts & solvents 2

HCID 176Acetic AcidSolventHCID 887MethanolSolvent

Procedure

To a solution of 2,3,5,6-tetrahydro-1H-pyrrolo[2,1-a]isoquinolinium chloride (prepared by the method of S. Akaboshi, T. Kutsuma, and K. Achiwa, J. Pharm. Bull., 1960, 8, 14, from N-(2-phenylethyl)-4-chlorobutyramide (56.4 g, 0.25 mol) and extracted into isopropanol-dichloromethane) in methanol (700 ml) and acetic acid (50 ml) at 0° C. was added portionwise sodium cyanoborohydride (19 g) over 1 h. After stirring overnight, the solvent was concentrated in vacuo. The residue was dissolved in dilute sodium hydroxide and was extracted twice with dichloromethane. The dried (magnesium sulfate) organic phase was concentrated to give an oil which was distilled using a Kugelrohr distilling apparatus, b.p. 100° C. at 0.25 mm, to give the title compound (30.4 g, 70%) as a pale yellow oil.

Workup

  1. concentrationthe solvent was concentrated in vacuo
  2. dissolutionThe residue was dissolved in dilute sodium hydroxide
  3. extractionwas extracted twice with dichloromethane
  4. dry with materialThe dried (magnesium sulfate) organic phase
  5. concentrationwas concentrated
  6. customto give an oil which
  7. distillationwas distilled
  8. distillationdistilling apparatus, b.p. 100° C. at 0.25 mm

Sources & evidence

ORD record
ord-ab397a1db59342e2a03cd8c50d2aecc7
Source dataset
uspto-grants-2000_10
Patent number
US06140322

Reaction notes

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