Carbamic acid, N-(2,2-dimethyl-3-oxocyclobutyl)-, 1,1-dimethylethyl ester → HCID 131733579, compound

HRID 1749433Notes

Reaction equation

HRID 1749433 reaction equation
[CH3:1][C:2]1([CH3:15])[C:5](=[O:6])[CH2:4][CH:3]1[NH:7][C:8](=[O:14])[O:9][C:10]([CH3:13])([CH3:12])[CH3:11].[CH3:16][Li]>C1COCC1>[OH:6][C:5]1([CH3:16])[CH2:4][CH:3]([NH:7][C:8](=[O:14])[O:9][C:10]([CH3:13])([CH3:12])[CH3:11])[C:2]1([CH3:15])[CH3:1]

Participants

4

Reactant 2

HCID 84679804Carbamic acid, N-(2,2-dimethyl-3-oxocyclobutyl)-, 1,1-dimethylethyl esterHCID 178418348HCID 178418348, compound

Product 1

HCID 131733579HCID 131733579, compoundYield 30%

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent

Procedure

To a solution of tert-butyl (2,2-dimethyl-3-oxocyclobutyl)carbamate (1.0 equiv.) in anhydrous THF (0.15 M) under nitrogen was added methyllithium (1.6 M in ether, 4.0 equiv.) drop-wise, keeping the temperature below −70° C. The mixture was stirred at this temperature for 1 h. The mixture was quenched with aqueous solution of ammonium chloride and the mixture was extracted with ethyl acetate, 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 (5% to 25% ethyl acetate in petroleum ether) to afford the title product (30% yield). 1H NMR (400 MHz, CDCl3) δ (ppm) 4.65-4.52 (m, 1H), 3.60-3.49 (m, 1H), 2.37-2.28 (m, 1H), 1.84-1.76 (m, 1H), 1.66 (s, 1H), 1.44 (s, 9H), 1.28 (s, 3H), 1.06 (s, 3H), 1.01 (s, 3H); MS (ESI) m/z 230.2 [M+H]+.

Workup

  1. customthe temperature below −70° C
  2. customThe mixture was quenched with aqueous solution of ammonium chloride
  3. extractionthe mixture was extracted with ethyl acetate
  4. washwashed with aqueous solution of sodium bicarbonate and brine
  5. dry with materialdried over anhydrous sodium sulfate
  6. filtrationfiltered
  7. concentrationThe filtrate was concentrated under vacuum
  8. customthe residue was purified by silica gel column chromatography (5% to 25% ethyl acetate in petroleum ether)

Sources & evidence

ORD record
ord-59913087d4d44ba69d4ac38c998465c0
Source dataset
uspto-grants-2015_10
Patent number
US09156798B2

Reaction notes

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