Objective

To check the stability of the furan ring of 5-Methylfurfurylamine in TFA to investigate the behavior of furan containing Ugi products.

Procedure

In an NMR tube 5-methyl furfurylamine (20uL, 0.179mmol, 0.179M) is dissolved in CDCl3 (500uL). An initial HNMR of the solution is obtained on a 300MHz NMR instrument. To the solution in the NMR tube, Trifluroaceticacid (500uL, 50%) is added and the reaction is monitored by NMR.

Results

5MFA HNMR
73A
40min HNMR
2h48min HNMR
After 6 days
HOMODEC of 73A

Discussion

  1. The methylene group is apparently the quartet at 4.3 ppm with a coupling of 6 Hz. The fact that it is coupling to NH3+ is confirmed by a selective homonuclear decoupling experiment ( HOMODEC of 73A ). This was done by irradiating the NH3+ peak at 7.05 ppm, as a result of which the CH2 quratet collapsed to a singlet

Conclusion

After 6 days it is clear that there is nothing happening to the furan ring. The 5-methylfurfurylammonium trifluroracetate is stable and does not lose its furan character or the methyl group in 1:1 TFA/CDCl3.

Log


2007-03-20

12:30 Made-up a solution of 5-methyl furfurylamine (20uL) in CDCl3 (500uL)
12:45 Obtained HNMR of 5-MFA
13:20 Added TFA (500uL) to the above solution, obtrained (73A).
14:00 Obtained HNMR (t = 40min)
16:08 Obtained HNMR (t = 2h 48min)

2007-03-26

12:41 Obtained HNMR of 73A (t = 6 days)

2007-03-30

21:00 Obtained HOMODEC of 73A. The compound remained unchanged.

Tags

5-methylfurfurylamineInChI=1/C6H9NO/c1-5-2-3-6(4-7)8-5/h2-3H,4,7H2,1H3
TFA: InChI=1/C2HF3O2/c3-2(4,5)1(6)7/h(H,6,7)