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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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KBS23-5 - Azidation of 1-naphthylamine #146

Closed KlementineJBS closed 11 months ago

KlementineJBS commented 11 months ago

Link to HIRAC, and master page. Original method from J. Batten's PhD thesis, but a similar method is used by Babin et al..

KBS22 Azidation of 1-naphthylamine.docx

Previous attempt is #59

Reaction scheme

KBS23 reaction scheme (azidation of 1-naphthylamine)

Outcome

1.81 g, 77%

KlementineJBS commented 11 months ago
  1. Dissolved 1-naphthylamine (2.0211 g, 14.1 mmol) in HCl (3.4 M, 14 mL). Put in ice.
  2. Added sodium nitrite (1.2769 g, 18.5 mmol, 1.3 equiv.) dissolved in water (4 mL). Reaction immediately went brown/black and bubbled up - next time should add SLOWLY
  3. Left stirring on ice for 20 minutes
  4. Added NaN3 (1.1002 g, 16.9 mmol, 1.2 equiv.) and left stirring
  5. TLC at 2.45 pm indicated reaction was complete
  1. Quenched with 10 mL water
  2. Extracted with diethyl ether (3 x 60 mL)
  3. washed with sodium bicarb solution (2 x 90 mL) and brine (2 x 90 mL)
  4. Dried over mag sulphate and rotovapped down
KlementineJBS commented 11 months ago

Crude NMR indicated something was there but was very unclear. Decided to try a silica plug instead of column because no second spot is visible on TLC.

Crude yield: 2.0834 g. Dark red, viscous material.

Used ~ 2 cm silica in a 4 cm diameter sintered funnel. Washed through with 100 mL of 5% ethyl acetate in hexanes and collected this (plug 1). Then used 100 mL of straight hexane (plug 2).

Plug 1 vial: 15.7591 Full vial: 17.3210 Mass: 1.5619 g - strangely liquid/non viscous, bright red - 9.24 mmol, 66%

Plug 2 vial: 15.7536 Full vial: 16.0047 Mass: 251.1 mg, 1.49 mmol, 11%

KlementineJBS commented 11 months ago

H NMR results

All look good, actually - no real sign of impurity except for colour.

KBS23-5 crude and silica plugs.pdf

KBS23-5 cr_1.zip KBS25-3 plug 1_1.zip KBS25-3 plug 2_1.zip

KlementineJBS commented 11 months ago

Tried using charcoal to lift coloured impurity from plug 1. Dissolved in 15 mL ethyl acetate, added 1/2 spatula charcoal, filtered through celite. Didn't seem to make much difference to the colour.

Need to do a Q NMR to confirm purity. @KlementineJBS

KlementineJBS commented 11 months ago

Charcoal-purified sample looks identical. Slight loss of yield, likely due to handling.

KBs23-5 silica plugs and charcoal.pdf KBS23-5 plug 1 charcoal_1.zip