FufurylCleavage-UCExp082.png

Objective

To obtain the Boc-deprotected free amine of the ugi product (064C) from Exp064

Procedure

Dissolved 55 mg (0.109 mmol) of the Ugi product 64C-2 from Exp064 in 500 uL anydrous chloroform in a round bottom flask. Then 500uL of trifluoroacetic acid was added to the above solution (50% solution in anhydrous chloroform). After 2 hours the remaining acid was evaporated from the reaction mixture by a high vac connected rotovap with KOH pellets in the traps. Then 10% NaOH (5 mL) solution was added to the round bottom flask, then dichloromethane (3 mL) was added to it, the brown oily contents were mixed well by squirting. The contents were then transferred to a centrifuge tube and the organic layer was pipetted out. To the aqueous layer dichloromethane (3 mL)was added again to extract the remaining free amine. The organic layers were combined, dried using anhydrous MgSO4, centrifuged the soild out. The dry organic layer was then rotovaped / vacuumed to remove the solvent. The product was weighed and analyzed by NMR spectroscopy.

Results

64C
H NMR in CDCl3
84A
H NMR of 82A
HOMODEC of 82A (Peak irradiated - 8.3 ppm -peak coupled to it : 5.53
A close-up of the 5-7 ppm of HOMODEC

Discussion

Since the Deboc process in 50% TFA takes less than 10min, this reaction went too far..and the nmr has become complicated for analysis. Therefore this experiment will be aborted.
A HOMODEC of 82A indicates that a doublet at 8.27 ppm is coupled to another signal at 5.5 ppm, which will be the focus in future experiments so as to accomplish an assignment for the peaks.

Conclusion

Experiment aborted.

Log

2007-03-30

12:50 Dissolved the ugi product (55 mg 01.109 mmol) in anhydrous chloroform (500 uL) in a round bottom flask (25 mL)
12:55 Added trifluroracetic acid (500 uL) to it.
14:55 Started rotovaping the acid from the round bottom flask. KOH pellets were placed in the traps of the rotovap / high vac.
15:40 Removed from the rotovap, added 10% NaOH (5 mL), and dichloromethane (3 mL), mixed well by squirting using a transfer pipette.Then removed the bottom organic layer and set it asid. To the aqueous layer added dichloromethane (2 mL), mixed well, separated the organic layer in to the previously collected organic layer.
16:00 The combined organic layers were dried using anhydrous MgSO4.
16:30 Centrifuged the solid (MgSO4) from the dry organic layer.
16:40 Set on a rotovap / vac.
15:15 Removed from the rotovap and obtained 82A (43.8 mg)
19:34 Obtained H NMR of 82A


Tags

Ugi064:InChI=1/C30H37N3O7/c1-20-12-14-23(39-20)19-33(26(34)18-32-29(36)40-30(2,3)4)27(22-13-15-24(37-5)25(16-22)38-6)28(35)31-17-21-10-8-7-9-11-21/h7-16,27H,17-19H2,1-6H3,(H,31,35)(H,32,36)
Amine:InChI=1/C25H29N3O5/c1-17-9-11-20(33-17)16-28(23(29)14-26)24(19-10-12-21(31-2)22(13-19)32-3)25(30)27-15-18-7-5-4-6-8-18/h4-13,24H,14-16,26H2,1-3H3,(H,27,30)