tag:blogger.com,1999:blog-4387100009341358284.post58804967368431720..comments2024-03-12T09:55:15.923+01:00Comments on Curly Arrow: Diazomethane and the Arndt-Eistert HomologationDaniel Sejerhttp://www.blogger.com/profile/12498255536497699232noreply@blogger.comBlogger5125tag:blogger.com,1999:blog-4387100009341358284.post-50213468594611983952013-06-12T20:17:15.586+02:002013-06-12T20:17:15.586+02:00@Jurgen, Dammit for some reason Blogger stopped no...@Jurgen, Dammit for some reason Blogger stopped notifying me of comments so I'm only seeing your question now. We have very poor experience with TMS-diazomethane. Generally, we find that if it works it is very messy. The only smooth reaction with this stuff we had was in making methylesters. So we gave up on the stuff years ago and just use diazomethane instead. D! Daniel Sejerhttps://www.blogger.com/profile/12498255536497699232noreply@blogger.comtag:blogger.com,1999:blog-4387100009341358284.post-55642156652338828952013-04-05T15:41:41.328+02:002013-04-05T15:41:41.328+02:00Hello,
Do you have experience in using TMSCHN2 (co...Hello,<br />Do you have experience in using TMSCHN2 (conditions?) for diazoketone synthesis from the chloroformate activated carboxylic acids? I would love to plan an Arndt-Eistert homologation, and would like to use TMSCHN2 if possible. (just to be sure on the safety part :-) )<br />Some years ago I have used TMSCHN2 to make diazoketones from acid chlorides (works well!), but the current Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-4387100009341358284.post-38862582791096967052013-03-07T09:28:35.495+01:002013-03-07T09:28:35.495+01:00@ChristianPFC, Cool that your are using diazometha...@ChristianPFC, Cool that your are using diazomethane but your really should not pipette the solution. The edge of a pipette is enough to make it go off. It's only a question of time before it happens. Instead you should use a clear seal joint sep. funnel. Remove the aqueous layer and then add the ether solution directly from the sep. funnel, please! I know of pasteur pipette induced Daniel Sejerhttps://www.blogger.com/profile/12498255536497699232noreply@blogger.comtag:blogger.com,1999:blog-4387100009341358284.post-43327586142531852182013-03-07T08:43:16.389+01:002013-03-07T08:43:16.389+01:00Having done a few esterifications with diazomethan...Having done a few esterifications with diazomethane, I have to say I just love this reagent! You titrate your acid until the solution stays yellow (does not work if you have colored substance or impurities) and destroy the excess with AcOH.<br /><br />There are procedures that do not require destillation, I used N-methyl-N-nitroso urea (add to ice cold aqueous KOH stirred with ether, the Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-4387100009341358284.post-49765658250750241742012-12-11T22:51:54.348+01:002012-12-11T22:51:54.348+01:00Awesome.
I've always thought using aspartate ...Awesome.<br /><br />I've always thought using aspartate to make β3-peptide analogues was rather clever, as that sidesteps the need for diazomethane.<br /><br />(ex. http://www.sciencedirect.com/science/article/pii/S1570963908000113)Brandonhttp://chemtips.wordpress.comnoreply@blogger.com