Water → HCID 9859144, compound

HRID 857445Notes

Reaction equation

HRID 857445 reaction equation
[Cl:1][C:2]1[CH:3]=[CH:4][C:5]2[CH:6]=[C:7]3[CH2:14][NH:13][CH2:12][CH2:11][N:8]3[C:9]=2[CH:10]=1.C([BH3-])#N.[Na+].O.[OH-].[NH4+]>C(O)(=O)C>[Cl:1][C:2]1[CH:3]=[CH:4][C:5]2[CH2:6][CH:7]3[CH2:14][NH:13][CH2:12][CH2:11][N:8]3[C:9]=2[CH:10]=1

Participants

6

Reactant 4

HCID 962WaterHCID 14923Ammonium HydroxideHCID 5003444Sodium cyanoborohydrideHCID 21868720HCID 21868720, compound

Product 1

HCID 9859144HCID 9859144, compoundYield 64.2%

Reagents, catalysts & solvents 1

HCID 176Acetic AcidSolvent

Procedure

To a stirred solution of 7-chloro-1,2,3,4-tetrahydropyrazino[1,2-a]indole (1.185 g, 5.73 mmol) in acetic acid (40 mL) under Ar at 10° C. was added portion-wise over 5 min sodium cyanoborohydride (1.19 g, 18.94 mmol). The resultant mixture was allowed to warm to ambient temperature, and was stirred for 24 h. The mixture was poured into water (200 mL) and was basified (pH 8–9) by the careful addition, with cooling, of ammonium hydroxide (60 mL) over 5 min. The basified mixture was extracted with chloroform (3×200 mL), the combined organic extracts washed with brine (200 mL), dried (magnesium sulfate), and concentrated in vacuo. The residue was purified by flash chromatography [SiO2; ethyl acetate-methanol-ammonium hydroxide (90:8:2)] to afford the title compound (768 mg, 64%) as a colourless oil: NMR δH (400 MHz, CDCl3) 1.60 (1H, br s), 2.50 (1H, ddd, J 15.1, 9.0, 1.0 Hz), 2.74 (1H, dd, J 11.5, 10.5 Hz), 2.79–2.99 (4H, m), 3.04 (1H, dd, J 11.5, 3.5 Hz), 3.42–3.52 (2H, m), 6.37 (1H, d, J 2.0 Hz), 6.57 (1H, dd, J 7.5, 2.0 Hz) and 6.92–6.96 (1H, m).

Workup

  1. additionby the careful addition
  2. extractionThe basified mixture was extracted with chloroform (3×200 mL)
  3. washthe combined organic extracts washed with brine (200 mL)
  4. dry with materialdried (magnesium sulfate)
  5. concentrationconcentrated in vacuo
  6. customThe residue was purified by flash chromatography [SiO2; ethyl acetate-methanol-ammonium hydroxide (90:8:2)]

Sources & evidence

ORD record
ord-8afdd8301355433582a5a08589dc0623
Source dataset
uspto-grants-2006_12
Patent number
US07145009B2

Reaction notes

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