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KlementineJBS / USYD_PhD_ELN

This repository forms the electronic laboratory notebook (ELN)for Klementine Burrell-Sander's PhD's
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KBS40-1 - NBS reaction on 2-acetyl-5-bromopyridine #122

Closed KlementineJBS closed 9 months ago

KlementineJBS commented 11 months ago

Link to HIRAC.

HIRAC NBS reaction Breaking Good.docx

Reaction scheme

KBS40 NBS reaction on 2-acetyl-5-bromopyridine

Outcome

361.3 mg, of which 359.4 mg is calculated to be mono- or di-brominated product = 89%

KlementineJBS commented 11 months ago
  1. Dissolved SM (251.9 mg, 1.26 mmol) in acetonitrile (50 mL)
  2. Added tosic acid (339 mg, 1.97 mmol, 1.6 equiv.) and NBS (274 mg, 1.54 mmol, 1.2 equiv.)
  3. Left stirring at 85 C from 4 pm
KlementineJBS commented 11 months ago

TLC at 3.30 pm indicated reaction was not yet complete, but in progress.

  1. Added additional tosic acid (184 mg, 1.07 mmol, 0.8 equiv.) and NBS (144 mg, 0.752 mmol, 0.6 equiv.) and left stirring at 85 C
KlementineJBS commented 11 months ago

TLC indicated reaction was not yet complete but worked up anyway.

  1. Rotovapped off MeCN
  2. Dissolved in 25 mL DCM
  3. Washed with water (2 x 25 mL) and brine (25 mL)
  4. Dried over mag sulphate and rotovapped down

Vial: 16.0855 Full vial: 16.4468 Mass: 361.3 mg (99% conversion)

KlementineJBS commented 11 months ago

H NMR

Analysis of integrals suggests 99% conversion rate. NMR of SM included for reference. Peak at 7.50 assumed to be from the di-bromoketone.

Bromination percentage calculations.xlsx KBS40-1 cr.pdf KBS40-1 cr_1.zip 2-acetyl-5-bromopyridine_1.zip