2-Acetylhydroquinone → Tert-butyl 6-hydroxy-4-oxospiro[chromane-2,4'-piperidine]-1'-carboxylate

HRID 38050Notes

Reaction equation

HRID 38050 reaction equation
[CH3:1][C:2]([C:4]1[CH:9]=[C:8]([OH:10])[CH:7]=[CH:6][C:5]=1[OH:11])=[O:3].[C:12]([O:16][C:17]([N:19]1[CH2:24][CH2:23][C:22](=O)[CH2:21][CH2:20]1)=[O:18])([CH3:15])([CH3:14])[CH3:13].N1CCCC1>CO>[C:12]([O:16][C:17]([N:19]1[CH2:24][CH2:23][C:22]2([CH2:1][C:2](=[O:3])[C:4]3[CH:9]=[C:8]([OH:10])[CH:7]=[CH:6][C:5]=3[O:11]2)[CH2:21][CH2:20]1)=[O:18])([CH3:15])([CH3:13])[CH3:14]

Participants

5

Reactant 3

HCID 102792-AcetylhydroquinoneHCID 31268PyrrolidineHCID 735900tert-Butyl 4-oxopiperidine-1-carboxylate

Product 1

HCID 59674420Tert-butyl 6-hydroxy-4-oxospiro[chromane-2,4'-piperidine]-1'-carboxylateYield 82.6%

Reagents, catalysts & solvents 1

HCID 887MethanolSolvent

Procedure

A solution of 2,5-dihydroxyacetophenone (15 g, 98 mmol), 4-oxo-piperidine-1-carboxylic acid tert-butyl ester (20 g, 100 mmol) and pyrrolidine (21 mL, 260 mmol) in methanol (146 mL) was stirred at reflux for 23 h and concentrated under vacuum to produce a red oily crude material. The oily crude material was purified by ISCO (330 g column) chromatography using 27 to 80% ethyl acetate in hexane to afford the product of step 1 (27 g, 82%), mp 72-74° C. (ethyl acetate, ether and hexane), MS m/z=332 (M−H).

Workup

  1. temperatureat reflux for 23 h
  2. concentrationconcentrated under vacuum
  3. customto produce a red oily crude material
  4. customThe oily crude material was purified by ISCO (330 g column) chromatography

Sources & evidence

ORD record
ord-ebc0523c969b4ce4b6c8c3c29fe056e6
Source dataset
uspto-grants-2013_09
Patent number
US08524713B2

Reaction notes

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