Ben picked up the Trichemist Cup 23, but was whisked away to a strange place. When he and Ryan came to, he heard a shrill voice say “Kill the spare.” A flash of green light and Ryan collapsed in a heap next to Ben. The evil Lord Koreeda, the counterpart of the beloved headmaster and writer, had risen through a mixture of dark, advanced chemistry, rebuilding his body. Â
Ben rises to meet the challenge of Lord Koreeda. They have a faceoff in the graveyard in Little Hangleton. But something strange happens…
“What’s going on with our test tubes?”
“I don’t know”
“Something is popping out of them”
“Is it the ghost of Ryan and my parents and Bertha Jorkins and Frank Bryce and Wormtail’s hand and all that stuff?”
“No you dolt. It’s the curtius rearrangement!”
“AHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHH”
The Curtius rearrangement is a process that involves the rearrangement of an acyl azide, a carbonyl bound to N3, to an isocyanate, R-N=C=O, which can be trapped by a variety of nucleophiles. Water can be used often to hydrolyze the isocyanate to an amine. When using tert-butanol, the reaction can generate Boc-protected amines, which are useful in organic synthesis.
The rearrangement itself is generally thought of as a two step process. In the first step, nitrogen gas is lost from the compound, forming an acyl nitrene, a highly unstable compound. After the formation of the acyl nitrene, the R-group migrates over to form the desired isocyanate. However, recent chemical evidence indicates that these two steps may be concerted, without the formation of a free nitrene intermediate.
Isocyanates themselves are very useful compounds that can form a urethane linkage with an alcohol, including polyurethanes. They can also react with amines to give urea, and with urea to give a biuret, all important compounds in biological synthesis. As used in this reaction, the Curtius Rearrangement facilitates the formation of a Bz-protected nitrogen, which allows it to be stable toward incoming compounds while synthesis on the rest of the compound is being undertaken.