Carbon tetrabromide → 5-(2-Bromoethyl)benzofurazan

HRID 1195673Notes

Reaction equation

HRID 1195673 reaction equation
O[CH2:2][CH2:3][C:4]1[CH:5]=[CH:6][C:7]2[C:8]([CH:12]=1)=[N:9][O:10][N:11]=2.C(Br)(Br)(Br)[Br:14].C1(P(C2C=CC=CC=2)C2C=CC=CC=2)C=CC=CC=1>C(Cl)Cl>[Br:14][CH2:2][CH2:3][C:4]1[CH:5]=[CH:6][C:7]2[C:8]([CH:12]=1)=[N:9][O:10][N:11]=2

Participants

5

Reactant 3

HCID 11205Carbon tetrabromideHCID 11776TriphenylphosphineHCID 150260865-(2-Hydroxyethyl)benzofurazan

Product 1

HCID 117758995-(2-Bromoethyl)benzofurazanYield 86.6%

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent2×

Procedure

A solution of 5-(2-hydroxyethyl) benzofurazan (1.0 g, 6.1 mmol) and carbon tetrabromide (2.6 g, 7.9 mmol) in methylene chloride (10 ml) was cooled to 0° C. A solution of triphenylphosphine (1.9 g, 7.3 mmol) in methylene chloride (10 ml) was added dropwise and the reaction was stirred for 5 minutes. Solvent evaporation and flash chromatography (silica gel, ethyl acetate-hexane, 5/95) gave 5-(2-bromoethyl)benzofurazan (1.2 g, 86%); 1H NMR (CDCl3) δ3.32(t,2H), 3.69(t,2H), 7.32(d,1H), 7.69(s,1H), 7.84(d,1H).

Workup

  1. customSolvent evaporation and flash chromatography (silica gel, ethyl acetate-hexane, 5/95)

Sources & evidence

ORD record
ord-bdf2f447e44b4e07b6c3df2a863432e3
Source dataset
uspto-grants-1992_05
Patent number
US05112824

Reaction notes

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