11-17-03 16:38
No 471381
swim recently did an experiment to see if they could make the ester of phenylalanine with isopropenol, heres what they said they did:
1g phenylalanine was disswolved in an excess of iso and a few ml of HCl were added.
this was heated to boiling in the microwave
when the solvent was evaporated round crystal structures started to form that where pinky coulre when scraped up.is this the ester?
"if i had a nickel for every penny id have a lottle o quaters!"-george turnbog (:o)
(Hive Bee)
11-17-03 17:21
No 471383
Measure the mp, then you know it :)
but i doubt that you made the ester (in good yeild), because HCl is not a common catalyst for ester formation.
better use a few drops of conc. Sulfuric acid.
Another good method is the use of a dean stark trap, together with toluene or benzene as solvent, and p-Toluene sulfonic acid as catalyst.
best wishes,
xicori
(Chief Bee)
11-19-03 00:07
No 471640
Also, ester formation usually takes hours rather than minutes. Use conventional heating under reflux, and model your ester synthesis after the mandelic acid ester syntheses in this document: ../rhodium /pemolin
The isopropanol ester of phenylalanine has a boiling point of 128-131°C/5 mmHg, and is not crystalline, but it may form a solid hydrochloride salt if you gas an anhydrous toluene solution of the washed and purified ester using anhydrous HCl gas.
(Newbee)
11-24-03 04:41
No 472769
ok but what about this:
as swim hasnt got anythin to reflux with swim was wanderin how long ud have to leave the reaction mix at room temp b4 the ester was formed in good yield....
swim was thinkin maybe a week?THEN IN WITH THE LITHIUM !!:p
SMACK WHORE IS AS SMACK WHORE DOES
(Chief Bee)
11-24-03 15:34
No 472866
I don't think that you will succeed to produce and/or isolate any product if you don't have any lab equipment. To purify and dry the ester you need to perform an acid/base wash followed by distilling off the solvent from the freebase ester before adding any lithium, or you'll quench one molar equivalent of the litium which will react with the hydrochloride part of the salt (which you need to make to be able to purify the ester without vacuum distillation).