Sodium borohydride → (1-Boc-6-fluoro-5-indazolyl)methanol

HRID 1952231Notes

Reaction equation

HRID 1952231 reaction equation
[F:1][C:2]1[CH:10]=[C:9]2[C:5]([CH:6]=[N:7][N:8]2[C:11]([O:13][C:14]([CH3:17])([CH3:16])[CH3:15])=[O:12])=[CH:4][C:3]=1[CH:18]=[O:19].[BH4-].[Na+]>CO.O.CCOC(C)=O>[OH:19][CH2:18][C:3]1[CH:4]=[C:5]2[C:9](=[CH:10][C:2]=1[F:1])[N:8]([C:11]([O:13][C:14]([CH3:17])([CH3:16])[CH3:15])=[O:12])[N:7]=[CH:6]2

Participants

6

Reactant 2

HCID 4311764Sodium borohydrideHCID 59490926HCID 59490926, compound

Product 1

HCID 59490881(1-Boc-6-fluoro-5-indazolyl)methanolYield 84.1%

Reagents, catalysts & solvents 3

HCID 887MethanolSolventHCID 962WaterSolventHCID 8857Ethyl AcetateSolvent

Procedure

A solution of tert-butyl 6-fluoro-5-formyl-1H-indazole-1-carboxylate (22E, 3.55 g, 13.4 mmol) in methanol (50.00 mL) was treated with NaBH4 (1.02 g, 26.9 mmol) at 0° C. and stirred for 1 h. The reaction mixture was diluted with water and EtOAc (500 mL). The organic layer was separated and washed with aq. HCl (1M, 200 mL), aq. NaOH (1M, 200 mL) brine (200 mL) dried (MgSO4), filtered, concentrated in vacuo and residue was purified by chromatography (SiO2, EtOAc/hexanes) to yield tert-butyl 5-(hydroxymethyl)-6-fluoro-1H-indazole-1-carboxylate (22F, 3.00 g; Yield=83.9%) as a colorless solid.

Workup

  1. customThe organic layer was separated
  2. washwashed with aq. HCl (1M, 200 mL), aq. NaOH (1M, 200 mL) brine (200 mL)
  3. dry with materialdried (MgSO4)
  4. filtrationfiltered
  5. concentrationconcentrated in vacuo and residue
  6. customwas purified by chromatography (SiO2, EtOAc/hexanes)

Sources & evidence

ORD record
ord-fb2669b3086f4bd684b9b473acca9caa
Source dataset
uspto-grants-2013_03
Patent number
US08404845B2

Reaction notes

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