From Meek et al, J. Org Chem, 1959, p. 1397:
To check further the speed of hydrolysis, tyrosine was synthesized by chloromethylating anisole, condensing it with methyl formamidomalonate and then heating with hydrobromic acid. In this preparation an ether cleavage was involved as well as hydrolysis and decarboxylation, but again the silver nitrate test was negative at the end of 60 minutes. Formamido compounds dissolve in hot hydrobromic acid in a few minutes as the formyl group comes off readily to form an amine salt. This rapid solution facilitates hydrolysis of the ester groups above that which would be found for acetamido or benzamidomalonates. As the average atmospheric pressure at the University of Colorado is about 630 mm. of mercury, solutions come to a boil at lower temperatures. As a result the length of time needed for hydrolysis may be less elsewhere.
The casualness at which older papers end is pretty amusing sometimes.
The lower boiling temperature in Colorado is an important thing to point out. I remember reading about a situation where someone had trouble reproducing a procedure in an old paper, and it turned out to be important to do the experiment at 16C and not normal room temperature. The paper was from a university in a cold climate in northern Europe before modern HVAC systems were widespread.
ReplyDeleteMy former group at Montana State University is still learning all sorts of fun things about cross-coupling mechanisms, all because our climate was so dry that we had to add extra water to get them to work. It's crazy how much of an impact lab location/climate can have on your work!
ReplyDeleteMy favorite thing that I've read from old papers was from the paper where Moses Gomberg reported the first persistent radicals in 1900, where he ends the paper with "This work will be continued and I wish to reserve the field for myself". In a later publication he then complains that someone else was working on it even though he called dibs.
ReplyDeleteHi Guys, have you noticed the astronomical cost of the regular organic solvents these days? I am looking to buy some for the lab...so thought of asking if you have any cheaper sources that you buy from other than VWR or Fischer? Thanks
ReplyDeleteFrom Gilbert Stork's last paper "At this point, we realized that we did not have enough material (a few milligrams) to go through the several steps for this conversion. One would have to restart the whole synthesis. But I (G.S.) am now 95 years old..." - Org. Lett. 2017, 19, 5150−5153.
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