Methanesulfonic Acid → 7-Methylcaprolactam

HRID 467475Notes

Reaction equation

HRID 467475 reaction equation
CS(O)(=O)=O.[CH3:6][CH:7]1[CH2:12][CH2:11][CH2:10][CH2:9][C:8]1=[O:13].[N-:14]=[N+]=[N-].[Na+]>COCCOC>[CH3:6][CH:7]1[NH:14][C:8](=[O:13])[CH2:9][CH2:10][CH2:11][CH2:12]1

Participants

5

Reactant 3

HCID 6395Methanesulfonic AcidHCID 114192-MethylcyclohexanoneHCID 33557Sodium Azide

Product 1

HCID 1372737-Methylcaprolactam

Reagents, catalysts & solvents 1

HCID 80711,2-DimethoxyethaneSolvent

Conditions

Temperature
23 °C

Procedure

Methanesulfonic acid (15 mL) was added to a solution of 2-methylcyclohexanone (2-1, 6.00 g, 53.5 mmol, 1 equiv) in DME (20 mL) at −40° C. Sodium azide (8.69 g, 134 mmol, 2.50 equiv) was added in four equal portions over 1 h as cooling was maintained. The cold bath was then removed and the reaction mixture was warmed to 23° C. and stirred for 20 h. The mixture was diluted with DME (20 mL) and basified to pH 9 with concentrated aqueous ammonium hydroxide solution. The resulting mixture was partitioned between brine (200 mL) and ethyl actetate (4×200 mL). The combined organic layers were dried over sodium sulfate and concentrated to give 7-methylazepan-2-one (2-2) as a pasty white solid. 1H NMR (300 MHz, CDCl3) δ 5.50 (br s, 1H), 3.50 (m, 1H), 2.43 (m, 2H), 2.05-1.30 (m, 6H), 1.21 (d, 3H,J=7.1 Hz).

Workup

  1. temperatureas cooling
  2. temperaturewas maintained
  3. customThe cold bath was then removed
  4. additionThe mixture was diluted with DME (20 mL)
  5. customThe resulting mixture was partitioned between brine (200 mL) and ethyl
  6. dry with materialThe combined organic layers were dried over sodium sulfate
  7. concentrationconcentrated

Sources & evidence

ORD record
ord-47cf7eae5da54c949c23f398c0661552
Source dataset
uspto-grants-2014_01
Patent number
US08623863B2

Reaction notes

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