Not that it'll be particularly noticeable, but I'm on holiday from tomorrow onwards as I take my mountain bike over to the French alps for an exciting week of trying not to break anything that'll prevent me from working in a lab. In the meantime, please enjoy this extract from our old lab copy of "Purification of Laboratory Chemicals":
The urea can then be coughed up, and then purified as described on page 355. All in a day's work.
Note: It seems that this particular 'remedy' is missing from 2003 and later editions, probably for fear of lawsuits.
Have you ever tried to look up famous chemists on Wikipedia only to end up misspelling their name or finding a more famous person who shares it? Although sometimes this can be frustrating, it can also be pretty funny. Here are a few amusing namesakes I discovered recently:
As well as being one of the leading figures in the organocatalytic revolution, according to wikipedia.org, "David McMillan is a British-Australian drug smuggler who is best known for being the only Westerner on record as having successfully escaped Bangkok's Klong Prem prison". A man of many talents. Apparently, Dave avoided recapture by his immediate acquisition of an umbrella once outside the prison walls... because escaped prisoners never carry umbrellas. Clearly a clever man.
2. Phil Baron
The real Phil Baran. Credit: Sexy Science
Although he tends to make the rest of us look bad and just won't stop writing review after review after review, I still get excited whenever he publishes something. Apart from all that chemistry and reviewing, I have just learned from the Phil Baron wikipedia page that he's also a "voice actor, puppeteer and songwriter who voiced Piglet in the Disney Channel live-action/puppet television series Welcome to Pooh Corner". Where does he find the time?
Here’s another poser for you: what do the two molecules below have in common? Hint: in contrast to last week’s mechanistic question, this is more to do with their history.
The answer is... a few things. Firstly, they were both proposed incorrectly as structures for two very well known chemicals. On the left is the originally assigned structure for Meldrum’s acid, a useful reagent for acylations, generation of ketenes and Knoevenagel reactions. On the right is Dewar benzene, one of a number of different structures considered by James Dewar (of Dewar flask fame) for benzene. When I look at these compounds, I’m shocked by the speed with which chemistry has moved forwards over the past hundred years. For example, although Kekulé proposed the correct structure of benzene sometime in the 1860’s it wasn’t actually confirmed until 1929 when Catherine Lonsdale, first female Fellow of the Royal Society, solved its structure using X-ray diffraction. That’s right: the structure of benzene wasn’t confirmed until four years after Sir Robert Robinson proposed the correct structure of morphine. And it only took another 30 years for the entire 64 kDa structure of haemoglobin to be solved! In fact, the size and complexity of molecules readily analysed with the kind of equipment found in any university chemistry department has leapt forward since 50 years ago. But we digress.
The last two weeks have seen me secure a postdoc in the US, pass my PhD viva and catch a nasty cold, leaving little time in my life for writing. Now that I've finally got a few spare hours I'm completely out of ideas for a post, so I'm just going to write about some nice oldschool mechanistic detective work from the 1970's that I came across recently. Enjoy!
Here's a tricky little problem that was set at the start of a postgraduate research symposium I attended back in July. It was printed on the programmes given out at the door with a deadline at the end of the two day conference and a cash prize up for grabs. So, all that was required for the glory and spoils was a mechanism that rationalised the following experimental outcome:
Once you've drawn a few things down, you'll quickly realise that the difficulty lies not in drawing a mechanism for formation of the product, but in getting those pesky labels in the right place. Give it a go, and then read on for more information and the solution!