Polyphosphoric acid is a mixture of phosphoric acids and its anhydrides:
I like it as an acid catalyst in organic synthesis - a lot of people hate it because it's so thick and hard to handle. The stuff is absolutely gooey mess; when you heat it up, it gets down to about the consistency of honey. The neat thing is that lots of stuff will go into it (it is a strong acid goo, after all), but once you quench your reaction with water, your stuff will often crash out.
During a blissful few months, I cranked out a series of Fischer indoles with the stuff. Everything seemed to work!
- Log in to post comments
More like this
The series of Breaking Bad chemicals continues (spoilers inside). Previously: phosphine, mercury fulminate. Today: hydrogen fluoride.
HF is just that, H-F, or a hydrogen bound to a fluorine. All the other acids in this group - HCl, HBr, HI - are gases. What we call "hydrochloric acid" is HCl in…
What is it about celebrity models and credulity towards woo?
Very early in the history of this blog, we first encountered Suzanne Somers, someone who underwent lumpectomy and radiation therapy for breast cancer, as well as radiation, but eschewed chemotherapy for "alternative" medicine. Guess to…
I know I spent a fair bit of time last week slapping down Mike Adams, creator of NaturalNews.com website. In reality, he richly deserved it, as he has richly deserved it many times in the past. Indeed, were I so inclined, I could devote this blog to nothing but the deconstruction of the quackery…
The phosphoramidite method of oligonucleotide synthesis has been invaluable. WIth a few reagents and an expensive machine, you can make any sequence of DNA or RNA. Purification can be a bit tricky, and it only gets worse as you get longer (once you're up to about 100 bases, you probably have a…
Iam requested for a simple method for making the polyphosphoric acid .
It is great stuff - how do you handle it? Because I am working right now with it to dehydrogenate some PAH and it is so messy I am thinking making it for each synthesis in situ - 300 degC, vacuum and whoops goes the H3PO4 - are there any special tools e.g. the honey spoon available?
Is there any replacement for this reagent or any equivalents