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

HRID 2249891Notes

Reaction equation

HRID 2249891 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

5

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 89.1%

Reagents, catalysts & solvents 2

HCID 180AcetoneSolventHCID 962WaterSolvent

Procedure

To a solution of (3,3-dimethyl-1,5-dioxa-spiro[5,5]undec-9-yl)-methyl-carbamic acid tert-butyl ester (1.27 g, 3.63 mmol, 1.0 eq.) in acetone (40 mL) and water (20 mL) was added PPTS (228 mg, 0.25 eq.) and the resulting reaction was heated to reflux overnight, cooled to room temperature, concentrated to 20 mL, poured in saturated NaHCO3 and extracted with 3×EtOAc. The combined organic layers were dried over Na2SO4, filtered and concentrated. The residue was purified by silica gel chromatography (hexanes to 20% EtOAc/hexanes) to give methyl-(4-oxo-cyclohexyl)-carbamic acid tert-butyl ester (735 mg, 88%) as a white solid.

Workup

  1. customthe resulting reaction
  2. temperaturewas heated
  3. temperatureto reflux overnight
  4. concentrationconcentrated to 20 mL
  5. additionpoured in saturated NaHCO3
  6. extractionextracted with 3×EtOAc
  7. dry with materialThe combined organic layers were dried over Na2SO4
  8. filtrationfiltered
  9. concentrationconcentrated
  10. customThe residue was purified by silica gel chromatography (hexanes to 20% EtOAc/hexanes)

Sources & evidence

ORD record
ord-154a0874c2e44c4090562397d264ee22
Source dataset
uspto-grants-2008_01
Patent number
US07314936B2

Reaction notes

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