Researcher

Jenna Mancinelli

Objective

To determine the solubility of Ugi Product 216-3A in methanol, ethanol, THF, toluene, acetonitrile, DMSO, and DMF by NMR.

Procedure

Label seven vials. Add a different solvent to each vial: 500 ul of methanol, 500 ul of ethanol, 500 ul of THF, 500 ul of toluene, 500 ul of acetonitrile, 150 ul of DMSO, 150 ul of DMF. Add enough Ugi Product 216-3A to each vial so that a solid is present in the vial. Place each vial in a heating-cooling thermostat with 60% water and propylene glycol bath set to 40.5°C for ten minutes, checking at five minute intervals. Remove the vials from the heating-cooling thermostat after ten minutes if precipitate is present. If solid is not present, add more Ugi Product 216-3A and begin again. Take H NMR of samples.

Results

SAMS
ONSCExp113-Spreadsheet-1

Discussion

The Ugi Product 216-3A is most soluble in DMSO, having a concentration of 0.28 M. In methanol, ethanol, toluene, and acetonitrile, the Ugi Product 216-3A was not as easily dissolved, having only a concentration between 0.00 M and 0.05 M.

The spectrum of the sample in which toluene was the solvent showed more peaks than expected in the 1.2 - 1.4 ppm range. This may be the result of impurities or some unknown chemical activity within the sample.[That one is not so problematic but take a look at the methanol NMR -anything strange? JCB] I'm not sure what the problem with the methanol NMR is. The methanol is made apparent by the doublet at 3.48 ppm for the CH3 and the quartet around 3.5 ppm for the OH. Also, the Ugi Product is evidented by the two (CH3)3 seen at 1.45 ppm and 1.33 ppm. The benzene can be seen at 6.76 ppm, while the CH2 groups appear between 3 -5 ppm and CH3 is visible at 2.1 ppm. Is there something missing or added that I have overlooked?

These results can be compared to those of Exp056. While the two Ugi Products have different chemical properties, they are both diamides and thus show similar solubility trends.

No H NMR was able to be obtained for the solution containing THF because the sample would not properly lock in the NMR device. No H NMR was able to be obtained for the solution containing DMF because there was no solvent remaining in the vial.

Conclusion

The solubility of Ugi Product 216-3A in different solvents has been determined.

Log

2009-06-22

16:30 In vials, mixed seven solutions of Ugi Product 216-3A with seven different solvents: methanol, ethanol, THF, toluene, acetonitrile, DMSO, and DMF. About 500 ul of methanol, ethanol, THF, toluene and acetonitrile were used. About 150 ul of DMSO and DMF were used. Ugi Product 216-3A was added to the solvents. Mixtures were made with solid remaining in the vials.
16:51 First mixture is placed for in the heating-cooling thermostat with 60% water and propylene glycol bath set to 40.5°C.
17:02 Mixture with methanol as solvent was removed from heating-cooling thermostat and left to sit at room temperature (26.5°C). At this point, a solid was present in the mixture.[If you are not doing fractional precipitation it will be faster to use the sonicator in a 40C bath for 30 min JCB]
17:12 Mixture with ethanol as solvent was removed from heating-cooling thermostat and left to sit at room temperature (26.5°C). At this point, a solid was present in the mixture.
17:29 Mixture with toluene as solvent was removed from heating-cooling thermostat and left to sit at room temperature (26.5°C). At this point, a solid was present in the mixture.
17:45 Mixture with acetonitrile as solvent was removed from heating-cooling thermostat and left to sit at room temperature (26.5°C). At this point, a solid was present in the mixture.
17:59 After having added solute to the mixture several times additional times, the mixture with THF as solvent was removed from heating-cooling thermostat and left to sit at room temperature (26.5°C). At this point, a very faint precense of a solid was apparent.
17:20 Mixture with DMSO as solvent was removed from heating-cooling thermostat and left to sit at room temperature (26.5°C). At this point, one white clump of solid was present in the vial.
17:35 Mixture with DMF as solvent was removed from heating-cooling thermostat and left to sit at room temperature (26.5°C). At this point, a solid was present in the mixture.
18:00 Mixtures left overnight in heating-cooling thermostat set to 25.0°C.[you should have left this at 40C JCB]

2009-06-23

11:00 Left samples in water bath maintained at 40.0°C.
17:00 Removed samples from water bath.
17:20 Left samples at room temperature.

2009-06-29
16:00 No solvent in sample with DMF.
16:15 Pipetted 700 ul CDCl3 into six NMR tubes labeled 1 through 6.
16:30 Pipetted 100 ul out of each sample, except sample with DMSO from which pipetted approximately 70 ul. 100 ul of each sample added to appropriate NMR tube. At this time the temperature in the lab was 23C.
16:40 Obtained H NMR of all six samples.