1H-Indole-6-carboxaldehyde → Indole

HRID 349114Notes

Reaction equation

HRID 349114 reaction equation
[NH:1]1[C:9]2[C:4](=[CH:5][CH:6]=[C:7](C=O)[CH:8]=2)[CH:3]=[CH:2]1.C(O)(=O)C.NC[C@@H](O)[C@@H](NC(=O)OC(C)(C)C)CC1C=C(F)C=C(F)C=1.[BH4-].[Na+]>CC(O)C>[NH:1]1[C:9]2[C:4](=[CH:5][CH:6]=[CH:7][CH:8]=2)[CH:3]=[CH:2]1

Participants

5

Reactant 3

HCID 27734351H-Indole-6-carboxaldehydeHCID 4311764Sodium borohydrideHCID 86594203tert-butyl (1S,2R)-3-amino-1-(3,5-difluorobenzyl)-2-hydroxypropylcarbamate acetate

Product 1

HCID 798IndoleYield 62.8%

Reagents, catalysts & solvents 1

HCID 3776IsopropanolSolvent

Procedure

To a stirred solution of 1H-indole-6-carbaldehyde (99 mg, 0.68 mmol) and tert-butyl (1S,2R)-3-amino-1-(3,5-difluorobenzyl)-2-hydroxypropylcarbamate acetate 3 (256 mg, 0.68 mmol) in 2-propanol (3 mL) was added sodium borohydride (30 mg, 0.82 mmol). The reaction mixture was stirred for 12 h., quenched with methanol, and concentrated under reduced pressure. Purification by flash column chromatography (silica, 1:1 ethyl acetate/hexanes) provided indole (50 mg): 1H NMR (300 MHz, CDCl3) δ 8.41 (br s, 1H), 7.60 (d, J=8 Hz, 1H), 7.38 (s, 1H), 7.21 (t, J=3 Hz, 1H), 7.04 (dd, J=8, 1 Hz, 1H), 6.71–6.73 (m, 3H), 6.61–6.68 (m, 1H), 6.53 (s, 1H), 5.38 (br s, 2H), 4.66 (d, J=9 Hz, 1H), 3.89 (s, 2H), 3.49–3.54 (m, 1H), 2.91–2.98 (m, 1H), 2.62–2.73 (m, 3H), 1.35 (s, 9H).

Workup

  1. customquenched with methanol
  2. concentrationconcentrated under reduced pressure
  3. customPurification by flash column chromatography (silica, 1:1 ethyl acetate/hexanes)

Sources & evidence

ORD record
ord-5298b78b56054d07a40b01a5514a9b5e
Source dataset
uspto-grants-2007_02
Patent number
US07176242B2

Reaction notes

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