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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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KBS29-1 - Appel reaction on KBS28 #57

Closed KlementineJBS closed 1 year ago

KlementineJBS commented 1 year ago

Link to HIRAC and master page. Method taken from J. Batten's PhD thesis (2022).

KBS29 - Appel reaction (CBr4).docx

Reaction scheme

KBS29 - Appel reaction (CBr4)

Outcome

235 mg (0.816 mmol), 75%

KlementineJBS commented 1 year ago

07.02.23

  1. Dissolved KBS28 (243 mg, 1.08 mmol) in DCM (2 mL)
  2. Added CBr4 (427 mg, 1.30 mmol, 1.2 equiv.) and triphenylphosphine (338 mg, 1.30 mmol, 1.2 equiv.)
  3. Put under nitrogen
  4. Left stirring from ~ 1.45 pm
image

TLC at 4.15 pm indicated incomplete conversion to Br derivative. (60% ethyl acetate in hexanes)

image
KlementineJBS commented 1 year ago

08.02.23

Reaction had gone dry overnight - was a thick, sticky residue resembling honey in colour and viscosity.

  1. Added DCM (3 mL)

TLC still indicated incomplete conversion at 9.30 am. Left to stir for a while and TLC'd again at 1.30 pm.

Still incomplete conversion. NMR'd reaction mixture to assess conversion.

image

Sample is very concentrated but appears to contain both SM (methylene peak around 5 ppm) and product (methylene peak is shifted downfield).

  1. Added additional CBr4 (214 mg, 0.653 mmol, 0.6 equiv.) and triphenylphosphine (166 mg, 0.633 mmol, 0.6 equiv.) and left stirring
KlementineJBS commented 1 year ago

09.09.23

Vial: 15.6106 Full vial: 15.8458 Mass: 235.2

H NMR

KBS29-1_1.zip KBS29-1.pdf

Strong evidence that Br product has formed (methylene peak has shifted from 4.98 to 4.74). Need to confirm by IR and determine an appropriate method for MS.

KlementineJBS commented 1 year ago

13.02.23

IR

KBS29-1.0.zip KBS29-1.pdf

KlementineJBS commented 1 year ago

14.02.23

Flushed with column with 100% ethyl acetate to see what else was left (as SM didn't seem to have come off). Obtained a yellow oil, similar in appearance to KBS23 or KBS28

H NMR was confusing/inconclusive -- while product has a peak at 4.74 and SM at 4.98, the material obtained in the flush had a peak at 4.84. May be due to incorrect referencing?

KBS29-1 flush_1.zip KBS29-1 column flush.pdf

KlementineJBS commented 1 year ago

Column details