Hydrogen Bromide → 2-Bromo-1-(oxolan-2-yl)ethan-1-one

HRID 1421791Notes

Reaction equation

HRID 1421791 reaction equation
[N+](=[CH2:3])=[N-].[O:4]1[CH2:8][CH2:7][CH2:6][CH:5]1[C:9](Cl)=[O:10].[BrH:12]>ClCCl>[Br:12][CH2:3][C:9]([CH:5]1[CH2:6][CH2:7][CH2:8][O:4]1)=[O:10]

Participants

5

Reactant 3

HCID 260Hydrogen BromideHCID 9550Diazomethane2×HCID 551254Tetrahydro-2-furancarbonyl chloride

Product 1

HCID 219089652-Bromo-1-(oxolan-2-yl)ethan-1-oneYield 77%

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent

Procedure

A stream of diazomethane (from N-methyl-N-nitrosotoluene-4-sulphonamide, 18.0 g) in argon (P. Lombardi, Chem. and Ind., 1990, (21), 708) was passed into a solution of (RS)-tetrahydrofuroyl chloride [prepared from (RS)-tetrahydrofuroic acid (3.48 g, 30 mmol) as described in Example 2(a)] in dichloromethane (60 ml) cooled in an ice bath. When the diazomethane addition was complete, 48% aqueous hydrogen bromide (5.6 ml, 33.2 mmol) was added. The mixture was stirred 0.25 h then washed twice with water, dried, concentrated and flash chromaographed on silica gel eluting with 10% ethyl acetate in hexane to give the title compound as a pale yellow oil (4.44 g, 77%); νmax (CH2Cl2) 1733, 1245, 1073 and 938 cm-1 ; δH (CDCl3) 1.85-2.35 (4H, m), 3.85-4.05 (2H, m), 4.20 (2H, s), 4.54 (1H, dd, J 6.1, 8.2 Hz). [Mass spectrum: +ve ion (ammonia) MNH4+ (210)].

Workup

  1. temperaturecooled in an ice bath
  2. washthen washed twice with water
  3. customdried
  4. concentrationconcentrated

Sources & evidence

ORD record
ord-694b334f78ae4ff8ac4dfd313f15fa99
Source dataset
uspto-grants-2000_06
Patent number
US06077952

Reaction notes

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