Sodium Azide → 2-(2-Azidoethyl)-5-bromo-7-chlorobenzofuran

HRID 2179400Notes

Reaction equation

HRID 2179400 reaction equation
CC1C=CC(S(O[CH2:12][CH2:13][C:14]2[O:15][C:16]3[C:22]([Cl:23])=[CH:21][C:20]([Br:24])=[CH:19][C:17]=3[CH:18]=2)(=O)=O)=CC=1.[N-:25]=[N+:26]=[N-:27].[Na+]>CN(C)C=O>[N:25]([CH2:12][CH2:13][C:14]1[O:15][C:16]2[C:22]([Cl:23])=[CH:21][C:20]([Br:24])=[CH:19][C:17]=2[CH:18]=1)=[N+:26]=[N-:27]

Participants

4

Reactant 2

HCID 33557Sodium AzideHCID 866680032-(5-Bromo-7-chlorobenzofuran-2-yl)ethyl 4-methylbenzenesulfonate

Product 1

HCID 866680042-(2-Azidoethyl)-5-bromo-7-chlorobenzofuranYield 75%

Reagents, catalysts & solvents 1

HCID 6228DimethylformamideSolvent

Conditions

Temperature
70 °C

Procedure

To a solution of the product of step C (2.3 g, 5.35 mmol) in dimethylformamide (11 mL) was added sodium azide (1.2 g, 18.73 mmol) at ambient temperature. The reaction mixture was heated at 70° C. for 2 h, cooled and quenched with water then extracted with ethyl acetate (2×15 mL). The combined organic extracts were dried over Na2SO4 and concentrated in vacuo to give the crude product which was purified by column chromatography (SiO2, 4:1 hexanes/ethyl acetate) providing 2-(2-azidoethyl)-5-bromo-7-chlorobenzofuran (1.2 g, 75%) as an off-white solid: 1H NMR (CDCl3, 400 MHz) δ 7.52-7.49 (m, 1H), 7.37-7.35 (m, 1H), 6.50 (s, 1H), 3.67 (t, J=6.8 Hz, 2H), 3.07 (t, J=6.8 Hz, 2H).

Workup

  1. temperaturecooled
  2. customquenched with water
  3. extractionthen extracted with ethyl acetate (2×15 mL)
  4. dry with materialThe combined organic extracts were dried over Na2SO4
  5. concentrationconcentrated in vacuo
  6. customto give the crude product which
  7. customwas purified by column chromatography (SiO2, 4:1 hexanes/ethyl acetate)

Sources & evidence

ORD record
ord-f7b1bc037543499a923c143918cd1abf
Source dataset
uspto-grants-2015_06
Patent number
US09067949B2

Reaction notes

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