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

HRID 1097582Notes

Reaction equation

HRID 1097582 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-4ceda26819e24e16a4edfaf59a325cc8
Source dataset
uspto-grants-2012_03
Patent number
US08143270B2

Reaction notes

Loading…