Potassium Carbonate → tert-butyl N-(2-oxocyclopentyl)carbamate

HRID 245052

Reaction equation

HRID 245052 reaction equation
[Br-].[K+].[OH:3][C@@H:4]1[CH2:8][CH2:7][CH2:6][C@H:5]1[NH:9][C:10](=[O:16])[O:11][C:12]([CH3:15])([CH3:14])[CH3:13].Cl[O-].[Na+].C(=O)([O-])[O-].[K+].[K+]>ClCCl.[Cl-].[Na+].CC1(C)CCCC(C)(C)[NH+]1[O-]>[O:3]=[C:4]1[CH2:8][CH2:7][CH2:6][CH:5]1[NH:9][C:10](=[O:16])[O:11][C:12]([CH3:14])([CH3:13])[CH3:15]

Participants

8

Reactant 4

HCID 11430Potassium CarbonateHCID 253877Potassium BromideHCID 23665760Sodium HypochloriteHCID 45091953(1R,2R)-trans-N-Boc-2-Aminocyclopentanol

Product 1

HCID 357962tert-butyl N-(2-oxocyclopentyl)carbamateYield 76.3%

Reagents, catalysts & solvents 3

HCID 101250832,2,6,6-Tetramethyl-piperidine 1-oxideCatalystHCID 5234Sodium ChlorideSolventHCID 6344DichloromethaneSolvent

Conditions

Temperature
5 °C

Procedure

2,2,6,6-Tetramethylpiperidine-N-oxide (2.2 g, 14.2 mmol) and potassium bromide (8.5 g, 71 mmol) are added to a solution of racemic trans-tert-butyl N-[2-hydroxycyclopentyl]carbamate (75 g, 283 mmol) in dichloromethane (285 mL). The mixture is cooled to 5° C. with stirring. A freshly prepared ice cooled (5° C.) sodium hypochlorite aqueous solution (766 mL, 566 mmol, pH adjusted to 7.5-8 by addition of 10 g of solid potassium carbonate) is added with stirring to the reaction mixture while keeping the temperature below 5° C. The mixture is stirred at 5° C. for an additional 30 min. The reaction mixture is diluted with saturated aqueous sodium chloride solution (150 mL). The organic layer is separated and evaporated. The oily red residue is purified over a silica gel pad, eluting with EtOAc/hexanes (1/3) to obtain the title compound as a cream colored solid (43 g, 76%). 1H-NMR (300 MHz, DMSO-d6) δ 6.99 (d, 1H, NH), 3.76 (q, 1H), 1.63-2.31 (m, 6H), 1.37 (s, 9H).

Workup

  1. additionis added
  2. stirringwith stirring to the reaction mixture
  3. customthe temperature below 5° C
  4. stirringThe mixture is stirred at 5° C. for an additional 30 min
  5. customThe organic layer is separated
  6. customevaporated
  7. customThe oily red residue is purified over a silica gel pad
  8. washeluting with EtOAc/hexanes (1/3)

Sources & evidence

ORD record
ord-168dca8190654a0589aeb29b2d568a89
Source dataset
uspto-grants-2014_02
Patent number
US08658693B2

Linked notes

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