(Diethylamino)sulfur trifluoride → Tert-butyl (2-fluoro-2-methylpropyl)carbamate

HRID 598045Notes

Reaction equation

HRID 598045 reaction equation
O[C:2]([CH3:13])([CH3:12])[CH2:3][NH:4][C:5](=[O:11])[O:6][C:7]([CH3:10])([CH3:9])[CH3:8].C(N(S(F)(F)[F:20])CC)C.C(=O)(O)[O-].[Na+]>ClCCl>[F:20][C:2]([CH3:13])([CH3:12])[CH2:3][NH:4][C:5](=[O:11])[O:6][C:7]([CH3:10])([CH3:9])[CH3:8]

Participants

5

Reactant 3

HCID 123472(Diethylamino)sulfur trifluorideHCID 516892Sodium BicarbonateHCID 11106129tert-Butyl 2-hydroxy-2-methylpropylcarbamate

Product 1

HCID 72698934Tert-butyl (2-fluoro-2-methylpropyl)carbamateYield 70.9%

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent

Procedure

A solution of tert-butyl 2-hydroxy-2-methylpropylcarbamate (19.2 g, 101 mmol) in dichloromethane (500 mL) was stirred at −78° C. under a nitrogen atmosphere, and (diethylamino)sulfur trifluoride (DAST)(18.0 g, 112 mmol) was added dropwise. The solution was allowed to warm to room temperature and stirred overnight. Saturated aqueous sodium bicarbonate (150 mL) was added. The organic layer was then separated and washed sequentially with saturated aqueous sodium bicarbonate (150 mL), water (150 mL), and brine (150 mL); dried over magnesium sulfate; filtered; and concentrated under reduced pressure. The resulting oil was purified by automated flash chromatography (FLASH 65I cartridge, eluting with 10% ethyl acetate in hexane) to provide 13.7 g of tert-butyl 2-fluoro-2-methylpropylcarbamate as a light yellow oil that crystallized overnight.

Workup

  1. customThe organic layer was then separated
  2. washwashed sequentially with saturated aqueous sodium bicarbonate (150 mL), water (150 mL), and brine (150 mL)
  3. dry with materialdried over magnesium sulfate
  4. filtrationfiltered
  5. concentrationand concentrated under reduced pressure
  6. customThe resulting oil was purified by automated flash chromatography (FLASH 65I cartridge, eluting with 10% ethyl acetate in hexane)

Sources & evidence

ORD record
ord-7e5ba8712eef419ab41071692cf4dab3
Source dataset
uspto-grants-2011_03
Patent number
US07897609B2

Reaction notes

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