Ethyl 2-(6-bromo-1-ethyl-1,3,4,9-tetrahydro-8-isopropylpyrano[3,4-b]indol-1-yl)acetate → 2-(6-Bromo-1-ethyl-1,3,4,9-tetrahydro-8-isopropylpyrano[3,4-b]indol-1-yl)ethanol

HRID 268688Notes

Reaction equation

HRID 268688 reaction equation
[Br:1][C:2]1[CH:3]=[C:4]2[C:8](=[C:9]([CH:11]([CH3:13])[CH3:12])[CH:10]=1)[NH:7][C:6]1[C:14]([CH2:20][C:21](OCC)=[O:22])([CH2:18][CH3:19])[O:15][CH2:16][CH2:17][C:5]2=1.[Li+].[BH4-].C1COCC1>C1COCC1>[Br:1][C:2]1[CH:3]=[C:4]2[C:8](=[C:9]([CH:11]([CH3:12])[CH3:13])[CH:10]=1)[NH:7][C:6]1[C:14]([CH2:20][CH2:21][OH:22])([CH2:18][CH3:19])[O:15][CH2:16][CH2:17][C:5]2=1

Participants

4

Reactant 2

HCID 59639731Ethyl 2-(6-bromo-1-ethyl-1,3,4,9-tetrahydro-8-isopropylpyrano[3,4-b]indol-1-yl)acetateHCID 131718764lithium borohydride THF

Product 1

HCID 111644512-(6-Bromo-1-ethyl-1,3,4,9-tetrahydro-8-isopropylpyrano[3,4-b]indol-1-yl)ethanolYield 80%

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent

Procedure

To a stirred solution of ethyl 2-(6-bromo-1-ethyl-1,3,4,9-tetrahydro-8-isopropylpyrano[3,4-b]indol-1-yl)acetate (6.0 g, 0.015 mol) in THF (120 ml), was added 2.0 M solution of LiBH4/THF (20 ml, 0.30 mol) via syringe during 30 min under a nitrogen atmosphere at room temperature. The mixture was refluxed for 10 hr, cooled, quenched with water and 5% HCl, and extracted with EtOAc. The organic phases were combined and washed with brine, dried over MgSO4, and evaporated to give a residue, which was chromatographed on silica gel. Elution with hexane-EtOAc (7:3) gave the product (4.3 g, 80%). 1H NMR (300 MHz, CDCl3) δ 8.18 (b, NH), 0.92 (t, 3H), 1.35 (d, 6H), 1.98 (m, 3H), 2.19 (m, 1H), 2.54 (t, 1H), 2.75 (m, 2H), 3.17 (m, 1H), 3.71 (t, 1H), 4.03 (m, 2H), 7.13 (dd, 1H), 7.45 (d, 1H), 7.96 (b, NH). ESI (+) MS m/e=367 (MH+), ESI (−) MS m/e=365 (MH−).

Workup

  1. temperatureThe mixture was refluxed for 10 hr
  2. temperaturecooled
  3. customquenched with water and 5% HCl
  4. extractionextracted with EtOAc
  5. washwashed with brine
  6. dry with materialdried over MgSO4
  7. customevaporated
  8. customto give a residue, which
  9. customwas chromatographed on silica gel
  10. washElution with hexane-EtOAc (7:3)

Sources & evidence

ORD record
ord-58c1a997f42b45b0913914d0b8d2bd13
Source dataset
uspto-grants-2008_11
Patent number
US07446122B2

Reaction notes

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