To purify the crude ugi product from the combined filtrates obtained from Exp189-193 and Exp195-203


To the combined filtrates containing the crude ugi product obtained from Exp189-192 and Exp195-203, in a 500mL beacker, methanol (200mL) was added. The solution was set on a steam bath until most of the solid had dissolved. It was then filtered through a buchner funnel. The filterate was then capped and left for crystallization. After one hour when the solid had formed the solvent was decanted and the residue was wahed with methanol (3x3mL) each time filtering off the solvent. The powder obtained was spread-out on a watch glass and left in an oven at 60C for one hour. The dried ugi product was weighed and analyzed by NMR.


Characterization of 206A
HNMR (Labile H exchange) - Protons not exchanged.


Amide protons do not seem to be that labile...after the addition of D2O to the sample they still remain bonded to the Ugi diamide. You may have to pour into a vial and vortex for several minutes.


Purification was successful.


10:00 The filtrates obtained after parallel filtration from the optimization of ugi reaction reaction experiments (Exp189-Exp203) was collected in a 500mL beaker. Some of the filtrates had completely dried by now and some had solvent in it.
10:30 However, approximately 200 mL of methanol was added to this beaker containing the combined filtrates and set on a steam bath, until most of the solid had dissolved. There were still some particles that remained undissolved. This solution was filtrated hot using a buchner funnel.
11:30 The obtained clear filtrate in the beaker was covered with watch glass and set undisturbed for an hour and a half.
13:00 The solution had developed white residue/crystals at the bottom of the flask...The supernatant was decanted...
13:15 The solid was washed with a small amount was methanol (3x~3mL). The residue was filtered each time.
14:30 The obtained white powder was placed on a watch glass and left in an oven at 60C for one hour.
17:00 The dry solid was removed and weighed...This is 206A (1.3g) The mother liquor was saved.
17:00 Started a C13 NMR on a 500MHz varian unity inova (parameters set by the ChemSpiderman from ChemSpider).
09:30 Obtained a CNMR of 206A.
11:30 Obtained a HNMR.
11:35 Added D2O (~100uL) to the NMR tube, mixed it well by shaking the NMR tube vigorously for about 1min and then obtained another HNMR, to check for the labile NH (amide) exchange.
17:00 Mother liquor had developed crystals, it was filtered and the crystals were washed with methanol (3x3mL) and the product was left to dry in an oven at 60C
14:30 Obtained 206B (1.5g)


Inchi Key
Ugi adduct
InChI=1/C24H33N3O5/c1-23(2,3)26-21(29)20(17-11-8-7-9-12-17)27(16- ​18-13-10-14-31-18)19(28)15-25-22(30)32-24(4,5)6/h7-14,20H,15-16H2​