N-bromobutanimide → 2-Bromo-5-fluoro-3-methylbenzo[b]thiophene

HRID 226098Notes

Reaction equation

HRID 226098 reaction equation
[F:1][C:2]1[CH:3]=[CH:4][C:5]2[S:9][CH:8]=[C:7]([CH3:10])[C:6]=2[CH:11]=1.C1C(=O)N([Br:19])C(=O)C1>C(#N)C>[Br:19][C:8]1[S:9][C:5]2[CH:4]=[CH:3][C:2]([F:1])=[CH:11][C:6]=2[C:7]=1[CH3:10]

Participants

4

Reactant 2

HCID 67184N-bromobutanimideHCID 5968285-Fluoro-3-methyl-benzo[b]thiophene

Product 1

HCID 667212022-Bromo-5-fluoro-3-methylbenzo[b]thiopheneYield 95%

Reagents, catalysts & solvents 1

HCID 6342AcetonitrileSolvent

Procedure

A 3 neck 2 L round bottom flask is fitted with a septum, a mechanical stirrer, and stopper. The flask is charged with 5-fluoro-3-methylbenzothiophene (55.4 g, 0.311 moles) and acetonitrile (350 mL). The mixture is stirred with a mechanical stirrer and the reaction temperature is monitored. NBS is added portion wise. The reaction temperature rises slightly, and the reaction is cooled with ice water bath. A solid crashes out of solution. The solid is filtered and rinsed 2 times with a 1:1 mixture of acetonitrile and water (100 mL). The solid is dried in a vacuum oven overnight at room temperature to obtain the title product (69 g, 95%). 1H-NMR (DMSO-d6), δ 2.41 (s, 3H), 7.34 (td, J=10, 2 Hz, 1H), 7.69 (dd, J=10, 2 Hz, 1H), 8.04 (dd, J=9, 5 Hz, 1H) ppm.

Workup

  1. customA 3 neck 2 L round bottom flask is fitted with a septum, a mechanical stirrer, and stopper
  2. temperaturethe reaction is cooled with ice water bath
  3. filtrationThe solid is filtered
  4. washrinsed 2 times
  5. additionwith a 1:1 mixture of acetonitrile and water (100 mL)
  6. customThe solid is dried in a vacuum oven overnight at room temperature

Sources & evidence

ORD record
ord-a37a387646d84141965e77603084ece6
Source dataset
uspto-grants-2009_07
Patent number
US07557103B2

Reaction notes

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