tert-Butanol → Carbamic acid, N-(2,2-dimethyl-3-oxocyclobutyl)-, 1,1-dimethylethyl ester

HRID 1749409Notes

Reaction equation

HRID 1749409 reaction equation
[CH3:1][C:2]1([CH3:10])[C:5](=[O:6])[CH2:4][CH:3]1C(O)=O.C([N:13]([CH2:16]C)CC)C.C1(P(N=[N+]=[N-])(C2C=CC=CC=2)=[O:25])C=CC=CC=1.[C:35]([OH:39])([CH3:38])([CH3:37])[CH3:36].C(=O)(O)[O-].[Na+]>C1(C)C=CC=CC=1>[CH3:10][C:2]1([CH3:1])[C:5](=[O:6])[CH2:4][CH:3]1[NH:13][C:16](=[O:25])[O:39][C:35]([CH3:38])([CH3:37])[CH3:36]

Participants

7

Reactant 5

HCID 6386tert-ButanolHCID 8471TriethylamineHCID 199401P,P-Diphenylphosphinic azideHCID 2760812,2-dimethyl-3-oxocyclobutanecarboxylic acidHCID 516892Sodium Bicarbonate

Product 1

HCID 84679804Carbamic acid, N-(2,2-dimethyl-3-oxocyclobutyl)-, 1,1-dimethylethyl esterYield 16%

Reagents, catalysts & solvents 1

HCID 1140TolueneSolvent

Conditions

Temperature
100 °C

Procedure

To a solution of 2,2-dimethyl-3-oxocyclobutanecarboxylic acid (1.0 equiv.) and triethylamine (1.5 equiv.) in toluene (0.2 M) was added diphenylphosphoryl azide (1.5 equiv.) slowly at 0° C. The mixture was then stirred at 100° C. for 4 h. The reaction mixture was cooled to room temperature, and tert-butanol (2.5 equiv.) was added. The resulting mixture was then refluxed for 15 h. After reaction completion, aqueous solution of sodium bicarbonate was added, and the mixture was extracted with ethyl acetate, the organic layer was washed with aqueous solution of sodium bicarbonate and brine, dried over anhydrous sodium sulfate and filtered. The filtrate was concentrated under vacuum, the residue was purified by silica gel column chromatography (7% ethyl acetate in petroleum ether) to afford the title product (16% yield). 1H NMR (300 MHz, CDCl3) δ (ppm) 4.79 (br, 1H), 4.03-4.01 (m, 1H), 3.43 (dd, J1=18.0 Hz, J2=9.0 Hz, 1H), 2.94 (dd, J1=18.0 Hz, J2=6.9 Hz, 1H), 1.48 (s, 9H), 1.28 (s, 3H), 1.13 (s, 3H).

Workup

  1. temperatureThe reaction mixture was cooled to room temperature
  2. temperatureThe resulting mixture was then refluxed for 15 h
  3. additionwas added
  4. extractionthe mixture was extracted with ethyl acetate
  5. washthe organic layer was washed with aqueous solution of sodium bicarbonate and brine
  6. dry with materialdried over anhydrous sodium sulfate
  7. filtrationfiltered
  8. concentrationThe filtrate was concentrated under vacuum
  9. customthe residue was purified by silica gel column chromatography (7% ethyl acetate in petroleum ether)

Sources & evidence

ORD record
ord-4b1bb4d0198345fda8c35d69a401af43
Source dataset
uspto-grants-2015_10
Patent number
US09156798B2

Reaction notes

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