Sodium borohydride → Tert-butyl 4,6-dihydroxyspiro[chromane-2,4'-piperidine]-1'-carboxylate

HRID 38051Notes

Reaction equation

HRID 38051 reaction equation
[C:1]([O:5][C:6]([N:8]1[CH2:13][CH2:12][C:11]2([CH2:18][C:17](=[O:19])[C:16]3[CH:20]=[C:21]([OH:24])[CH:22]=[CH:23][C:15]=3[O:14]2)[CH2:10][CH2:9]1)=[O:7])([CH3:4])([CH3:3])[CH3:2].[BH4-].[Na+]>CO>[C:1]([O:5][C:6]([N:8]1[CH2:13][CH2:12][C:11]2([CH2:18][CH:17]([OH:19])[C:16]3[CH:20]=[C:21]([OH:24])[CH:22]=[CH:23][C:15]=3[O:14]2)[CH2:10][CH2:9]1)=[O:7])([CH3:4])([CH3:2])[CH3:3]

Participants

4

Reactant 2

HCID 4311764Sodium borohydrideHCID 59674420Tert-butyl 6-hydroxy-4-oxospiro[chromane-2,4'-piperidine]-1'-carboxylate

Product 1

HCID 59589022Tert-butyl 4,6-dihydroxyspiro[chromane-2,4'-piperidine]-1'-carboxylateYield 90.6%

Reagents, catalysts & solvents 1

HCID 887MethanolSolvent

Procedure

A solution of the product from step 1 (4.51 g, 13.5 mmol) in methanol (50 mL) was cooled to 15° C. and sodium borohydride was added slowly and the mixture was further stirred for 30 min and then concentrated. The crude residue was partitioned between methylene chloride and water and the aqueous layer was extracted twice with methylene chloride. The combined organics was washed with brine, dried (Na2SO4), filtered and concentrated to produce the product of step 2 (4.1 g, 90%), mp 171-173° C. (ethyl acetate, ether and hexane), MS m/z=334 (M−H).

Workup

  1. concentrationconcentrated
  2. customThe crude residue was partitioned between methylene chloride and water
  3. extractionthe aqueous layer was extracted twice with methylene chloride
  4. washThe combined organics was washed with brine
  5. dry with materialdried (Na2SO4)
  6. filtrationfiltered
  7. concentrationconcentrated

Sources & evidence

ORD record
ord-71916285e34248bb82eba746904f4993
Source dataset
uspto-grants-2013_09
Patent number
US08524713B2

Reaction notes

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