Exp095.JPG

Objective

To monitor the synthesis of a Ugi adduct from 3,4-dimethoxybenzaldehyde, Furfurylamine, tert-butyl isocyanide and Boc-Gly-OH in methanol.

Procedure

Dissolved 3,4-dimethoxybenzaldehyde (Veratradlehyde) (83 mg, 0.5 mmol) and Furfurylamine(FFA) (58.7 uL, 0.55mmol, 10% excess ) in 1 mL methanol-d4 in a 1 mL volumetric flask, immediately transferred the contents to an NMR tube to monitor the imine formation reaction. Once the aldehyde peak disappeared a solution of Boc-Gly-OH(8t = 47min7.5 mg, 0.5 mmol), and tert-butyl isocyanide(56.5 uL, 0.5 mmol) is made up in 1 ml volumeric flask in methanol-d4 is added to the preformed imine in the NMR tube. The reaction is monitored until a Ugi product is obtained.

Results

(Reactant NMRs from Exp054)
Veratradehyde
H NMR (from EXP054 at about 1 M in methanol-d4)
C NMR
Furfurylamine
H NMR
C NMR
tert-Butyl isocyanide
H NMR
C NMR
Boc-Gly-OH
H NMR
C NMR
95A
t = 16min
t = 24min
t = 26min
t = 33min
t = 47min
t = 49min
t = 51min
t = 55min
t = 56min
t = 60min
t = 70min
t = 72min
t = 74min
t = 76min
t = 77min
t = 79min
t = 80min
t = 82min
t = 84min
t = 85min
t = 88min
t = 130min
95B
t = 02min
t = 04min
t = 05min
t = 07min
t = 09min
t = 18min
t = 19min
t = 21min
t = 29min
t = 41min

Discussion

  1. It is evident from the large amine to aldehyde ratio in the first 95A NMRs that an inaccurate amount of starting materials was used to perform the reaction. Based on the ratio of amine and imine peaks to the residual CHD2OD peak at 3.3 ppm (about 0.1 M based on several spectra, including the 1M veratraldehyde starting solution in EXP054), the starting aldehyde concentration is approximately 0.05 M, 10 times more dilute than expected. By similar analysis the starting amine concentration is correct, at about 0.5 M. This looks like a decimal place mistake on the scale.

Conclusion

Experiment aborted.

Log

2007-04-24

19:13 Madeup a solution of veratraldehyde and furfurylamine in 1ml methanol-d4 in a volumetric flask. This is 95A
19:29 Obtained H NMR t = 16min
19:37 Obtained H NMR t = 24min
19:39 Obtained H NMR t = 26min
19:47 Obtained H NMR t = 33min
20:00 Obtained H NMR t = 47min
20:02 Obtained H NMR t = 49min
20:04 Obtained H NMR t = 51min
20:08 Obtained H NMR t = 55min
20:09 Obtained H NMR t = 56min
20:13 Obtained H NMR t = 60min
20:23 Obtained H NMR t = 70min
20:25 Obtained H NMR t = 72min
20:27 Obtained H NMR t = 74min
20:29 Obtained H NMR t = 76min
20:30 Obtained H NMR t = 77min
20:32 Obtained H NMR t = 79min
20:33 Obtained H NMR t = 80min
20:35 Obtained H NMR t = 82min
20:37 Obtained H NMR t = 84min
20:38 Obtained H NMR t = 85min
20:41 Obtained H NMR t = 88min
21:23 Obtained H NMR t = 130min
21:24 Added a solution of Boc Glycine and tert-Butylisocyanide in 1mL methanol-d4 to obtain 95B
21:26 Obtained H NMR t = 02min
21:28 Obtained H NMR t = 04min
21:29 Obtained H NMR t = 05min
21:31 Obtained H NMR t = 07min
21:33 Obtained H NMR t = 09min
21:42 Obtained H NMR t = 18min
21:43 Obtained H NMR t = 19min
21:46 Obtained H NMR t = 21min
21:53 Obtained H NMR t = 29min
22:04 Obtained H NMR t = 41min

Tags

3,4-dimethoxybenzaldehyde InChI=1/C9H10O3/c1-11-8-4-3-7(6-10)5-9(8)12-2/h3-6H,1-2H3
Furfurylamine InChI=1/C5H7NO/c6-4-5-2-1-3-7-5/h1-3H,4,6H2
tert-butyl isocyanideInChI=1/C5H9N/c1-5(2,3)6-4/h1-3H3
Boc-Gly-OHInChI=1/C7H13NO4/c1-7(2,3)12-6(11)8-4-5(9)10/h4H2,1-3H3,(H,8,11)(H,9,10)
Product InChI=1/C26H37N3O7/c1-25(2,3)28-23(31)22(17-11-12-19(33-7)20(14-17)34-8)29 (16-18-10-9-13-35-18)21(30)15-27-24(32)36-26(4,5)6/h9-14,22H,15-16H2,1-8H3,(H,27,32)(H,28,31)