KBS23-3 - Azidation of 1-naphthylamine

[KlementineJBS]

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 #54

Reaction scheme

Outcome

370 mg, 2.19 mmol, 65%

[KlementineJBS]

30.01.23

1. Dissolved 1-naphthylamine (482.4 mg, 3.37 mmol) in water (16 mL) and HCl (10.2 M (32%), 4 mL, 40.8 mmol)

Solution was pale purple in colour.

2. Cooled to 0 degrees and added NaNO2 (319.7 mg, 4.63 mmol, 1.4 equiv.)

Solution turned orange-brown and got darker with time.

3. Stirred for 15 minutes

4. Added NaN3 (264.6 mg, 4.07 mmol, 1.2 equiv.)

Solution bubbled up upon addition.

5. Left stirring at rt from 10.50 am

TLC at 11.35 indicated reaction was incomplete. See #54 - middle spot in RM is believed to be diazo intermediate.

TLC at 1.15 seemed to suggest reaction was complete.

Work up

6. Extracted with diethyl ether (4 x 20 mL)
7. Washed with NaHCO3 (2 x 50 mL) and brine (2 x 50 mL)
8. Dried over mag sulphate
9. Filtered and rotovapped

Solution was a deep red colour prior to rotovapping, and resulted in a dark red liquid.

Empty vial: 15.8044 Full vial: 16.1744 Mass: 370 mg

H NMR

Resembles crude NMR of previous attempts. Large peak at 4.75 ppm unaccounted for.

KBS23-3 cr_1.zip KBS23-3 crude.pdf

[KlementineJBS]

31.01.23

Fractions	Empty vial (g)	Mass (mg)	mmol	%
2	15.7852	40.2	0.238	7
3-4	15.5986	250.4	1.48	44
5-9	15.5812	10.7	0.0633	2
13-21	15.8042	46	0.272	8

Fractions 2 - 9 all seem to contain the desired azide. However, only fractions 2-4 will be carried through due to contamination visible in the sample 5-9.

Fraction 2 was obtained as a yellow wax. Fraction 3-4 was a dark red liquid. The source/nature of this strongly coloured dark red contaminant is unknown but does not seem to show up on NMR.

H NMR

KBS23-3 fractions 2-21.pdf

KBS23-2 F2_1.zip KBS23-2 F3-4_1.zip KBS23-2 F5-9_1.zip KBS23-2 F13-21_1.zip

Note - NMR files are mislabelled, all should be KBS23-3