KBS16-4 - Azidation of ferrocenylmethanol about usyd_phd_eln

[KlementineJBS]

23.06.22

1. Set up a dry 50 mL 2-neck flask under N2
2. Added 331.8 mg (1.54 mmol) via solution transfer (10 mL dry THF)
3. Added DPPA (0.4 mL, 1.85 mmol, 1.2 equiv.) and DBU (0.28 mL, 1.85 mmol, 1.2 equiv.)
4. Stirred from 10.15 am to 11.15 am (1 hr)
5. Heated to reflux at 11.15 am
6. Added NaN3 (116.9 mg, 1.69 mmol, 1.1 equiv.) at 1.15 pm
7. Left stirring at reflux
8. TLC at 4.30 pm indicated reaction was not yet complete

[KlementineJBS]

24.06.22

9. TLC at 9.45 am indicated reaction was still not complete.

Strangely, the order of spots is reversed as compared with previous attempt #10 . The azide is expected to appear further up the plate than the alcohol, as in #10, so unsure what is causing this. There also appears to be a second product in the SM - the SM used was from KBS15-3 (made in 2021) so this may be a decomposition product?

10. Added more DPPA (0.26 mL, 1.23 mmol, 0.8 equiv.) and DBU (0.18 mL, 1.23 mmol, 0.8 equiv.) at 10 am

11. TLC at 4pm indicated completion - used a fresher sample of SM (from NMR sample of 15-4).

13. Quenched with water (40 mL) and extracted with toluene (3 x 60 mL)
14. Washed with brine, dried over MgSO4 and rotovapped

[KlementineJBS]

27.06.22

Vial (empty) = 15.7808
Vial (full) = 16.5859
Mass = 0.8051 mg

NMR

1H NMR (300 MHz, CDCl3) δ 4.23, 4.20, 4.17, 4.12.

NMR indicates product formation but has lots of junk - probably ethyl acetate, DBU and DPPA.

KBS16-4 cr_1.zip
KBS16-4 cr processed.pdf

Will try to column before carrying through.

[KlementineJBS]

28.06.22

Ran a column with a gradient of ethyl acetate in hexanes, 0 - 10%. Fractions had 2 products by TLC -- first product largely in fractions 1 - 14 and second largely in fractions 16 - 30 (didn't check more closely).

Product

Vial (empty) = 15.9410
Vial (full) = 16.1768
Mass = 235.8 mg

0.978 mmol

Side product

Vial (empty) = 15.9786
Vial (full) = 16.0726

[KlementineJBS]

29.06.22

NMR

Product

1H NMR (300 MHz, Chloroform-d) δ 4.24 (s, 2H), 4.20 (s, 2H), 4.17 (s, 5H), 4.12 (s, 2H).

KBS16-4_1.zip
KBS16-4 processed.pdf

Mostly product, with some traces of ethyl acetate and water.

Side product

KBS16-4 SP_1.zip
KBS16-4 SP processed.pdf

Possibly some unreacted SM but largely grease/solvent impurities.

IR

KBS16-4.0.zip
KBS16-4.pdf

[KlementineJBS]

01.07.22

LRMS

20220701_KBS16-4.d.zip
KBS16-4.pdf