Carbon tetrabromide → 5-(2-Bromoethyl)benzofurazan

HRID 1781382Notes

Reaction equation

HRID 1781382 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 86,639,240%

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent2×

Procedure

A solution of 5-(2-hydroxyethyl)benzofurazan (1.0 g, 6.1 nmol) and carbon tetrabromide (2.6 g, 7.9 nmol) in methylene chloride (10 ml) was cooled to 0° C. A solution of triphenyl phosphine (1.9 g, 7.3 nmol) in methylene chloride (10 ml) was added dropwise and the reaction was stirred for 5 min. Solvent evaporation and flash chromatography (silica gel, ethyl acetate-hexane, 5/95) gave 5-(2 bromoethyl)benzofurazan (1.2 g, 86%); 1H NMR (CDCl3) δ: 3.32 (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-a044b14d95534fccb6fff56c706226ca
Source dataset
uspto-grants-1997_05
Patent number
US05633247

Reaction notes

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