Benzenesulfonic acid, 4-methyl-, compd. with pyridine (1:1) → tert-butyl N-methyl-N-(4-oxocyclohexyl)carbamate

HRID 252047Notes

Reaction equation

HRID 252047 reaction equation
[C:1]([O:5][C:6](=[O:22])[N:7]([CH:9]1[CH2:21][CH2:20][C:12]2(OCC(C)(C)C[O:13]2)[CH2:11][CH2:10]1)[CH3:8])([CH3:4])([CH3:3])[CH3:2].CC1C=CC(S([O-])(=O)=O)=CC=1.C1C=C[NH+]=CC=1>CC(C)=O.O>[C:1]([O:5][C:6](=[O:22])[N:7]([CH3:8])[CH:9]1[CH2:21][CH2:20][C:12](=[O:13])[CH2:11][CH2:10]1)([CH3:4])([CH3:3])[CH3:2]

Participants

4

Reactant 2

HCID 466102Benzenesulfonic acid, 4-methyl-, compd. with pyridine (1:1)HCID 66891864(3,3-Dimethyl-1,5-dioxa-spiro[5,5]undec-9-yl)-methyl-carbamic acid tert-butyl ester

Product 1

HCID 24820328tert-butyl N-methyl-N-(4-oxocyclohexyl)carbamateYield 87%

Reagents, catalysts & solvents 1

HCID 18366337Propan-2-one--water (1/1)Solvent

Procedure

A solution of (3,3-dimethyl-1,5-dioxa-spiro[5,5]undec-9-yl)-methyl-carbamic acid tert-butyl ester (9.53 g, 27.2 mmol, 1.0 eq.) and PPTS (2.1 g, 0.3 eq.) in acetone-water (2:1, 500 mL) was heated at 80° C. for 18 h, cooled to room temperature and concentrated to remove acetone. The residual aqueous solution was diluted with NaHCO3 and extracted with 2×EtOAc. The combined organic layer was dried over Na2SO4, filtered and concentrated. The crude product was purified by chromatography (20% to 50% EtOAc/hexanes) to give methyl-(4-oxo-cyclohexyl)-carbamic acid tert-butyl ester as a white solid (5.38 g, 87%).

Workup

  1. concentrationconcentrated
  2. customto remove acetone
  3. additionThe residual aqueous solution was diluted with NaHCO3
  4. extractionextracted with 2×EtOAc
  5. dry with materialThe combined organic layer was dried over Na2SO4
  6. filtrationfiltered
  7. concentrationconcentrated
  8. customThe crude product was purified by chromatography (20% to 50% EtOAc/hexanes)

Sources & evidence

ORD record
ord-dc8fbf935eeb49aea0a563ef7043f5a5
Source dataset
uspto-grants-2011_01
Patent number
US07868002B2

Reaction notes

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