Search results
Results from the WOW.Com Content Network
Pyrrole is an extremely weak base for an amine, with a conjugate acid pK a of −3.8. The most thermodynamically stable pyrrolium cation (C 4 H 6 N +) is formed by protonation at the 2 position. Substitution of pyrrole with alkyl substituents provides a more basic molecule—for example, tetramethylpyrrole has a conjugate acid pK a of +3.7.
2,5-Bis(hydroxymethyl)pyrrole is an organic chemical compound with formula C 6 H 9 O 2 N, or (HOCH 2) 2 (C 4 H 3 N). Its molecule can be described as that of pyrrole C 4 H 5 N with hydroxymethyl groups HO−CH 2 − replacing the two hydrogen atoms adjacent to the nitrogen atom. The compound is a white solid, soluble in water and acetone.
The starting material was an N-substituted pyrrole derivative, which was heated to convert it by a [1,5] sigmatropic shift to the isomer with a carbon bond between the pyrrole and pyridine rings, followed by methylation and selective reduction of the pyrrole ring using tin and hydrochloric acid.
A library of substituted pyrrole analogs can be quickly produced by using continuous flow chemistry (reaction times of around 8 min.). [10] The advantage of using this method, as opposed to the in-flask synthesis, is that this one does not require the work-up and purification of several intermediates, and could therefore lead to a higher ...
We put a lot of products to the test at AOL. Here are our favorites on sale for Black Friday, including Keen sandals, Allbirds sneakers, and noise cancelling headphones.
Jessica DeCristofaro was diagnosed with stage 4B Hodgkin’s lymphoma, a rare form of cancer, at 28 years old. Here, she shares her story and what doctors missed.
It keeps my house smelling (and looking) better. Traditional litter boxes tend to smell, so I appreciate that the Litter-Robot 4 helps trap odors to keep that used-litter scent out of my home.
Fragrance bottles. An aroma compound, also known as an odorant, aroma, fragrance or flavoring, is a chemical compound that has a smell or odor.For an individual chemical or class of chemical compounds to impart a smell or fragrance, it must be sufficiently volatile for transmission via the air to the olfactory system in the upper part of the nose.