Objective

To synthesize three Ugi products using 4-pyrenebutanoic acid in THF.

Discussion

From this experiment, it is clear that it is not possible to make a 1M solution of 4-pyrenebutanoic acid in THF. Therefore a 0.5M solution was prepared and used further. However once the acid solution was added to a solution of aldehyde and amine, it formed a precipitate. Therefore this experiment could not be progressed any further.

Conclusion

Experiment aborted

Log

2009-05-05

13:00 Weighed out 288.3 mg of 4-pyrenebutanoic acid in a 1mL volumetric flask.
13:20 Added THF (up to 1mL mark), parafilmed the stopper and set it in a sonicator with water temp recorded as 21C
13:40 Obtained a picture of the setting, temp 25C; height of water in the sonicator was equal to the height of the solution in the volumetric flask.
14:00 Unable to obtain the clear solution, temp 30C....continued sonication
15:00 No luck...solid still at the bottom of the v.flask. Temp 38C...continued sonication
17:00 Still not luck...temp 40C....aborted sonication, bubbles were observed being released in the flask. ..not sure if I observed any volume contraction....[Did you see bubbles rising and volume contraction? JCB]
19:20 Transferred the solution with the solid in the volumetric flask carefully in to a 2ml volumetric flask..carefully rinsed out the remaining solution from the previous flask with THF...collected the solution in to the new 2mL v. flask.
19:35 Made-up the solution to 2mL mark by adding required THF. This solution was set in the sonicator with water bath at 30C
20:00 The solution had turned clear ...This is a 0.5M 4-pyrenebutanoic acid solution in THF.
20:10 Labeled three vials 220-1, 220-2, 220-3.
20:16 Obtained a picture of the solution; volumetric flask containing 0.5M 4-pyrenebutanoic acid in THF.
20:20 Weighed out 39mg of 2-naphthaldehyde (0.25mmol) in vial 220-1; 37.3mg of dimethylaminobenzaldehyde (0.25mmol) in vial 220-2 and 29.3uL of p-tolualdehyde in vial 220-3
20:30 Added 125uL of 2M methylamine in THF solution to each vial. All aldehydes dissolved in methylamine solution.
20:40 Added 500uL of freshly prepared 0.5M 4-pyrenebutanoic acid in THF to each vial.
21:45 Soon after the addition of the acid..all solutions formed ppts .....therefore obtained a picture of the vials, with ppts.