Search results
Results from the WOW.Com Content Network
The Hantzsch pyridine synthesis typically uses a 2:1:1 mixture of a β-keto acid (often acetoacetate), an aldehyde (often formaldehyde), and ammonia or its salt as the nitrogen donor. First, a double hydrogenated pyridine is obtained, which is then oxidized to the corresponding pyridine derivative.
The cyclobutadienide (2−) ion, however, is aromatic (6 electrons). An atom in an aromatic system can have other electrons that are not part of the system, and are therefore ignored for the 4n + 2 rule. In furan, the oxygen atom is sp² hybridized. One lone pair is in the π system and the other in the plane of the ring (analogous to C-H bond ...
Heteroarenes are aromatic compounds, where at least one methine or vinylene (-C= or -CH=CH-) group is replaced by a heteroatom: oxygen, nitrogen, or sulfur. [3] Examples of non-benzene compounds with aromatic properties are furan, a heterocyclic compound with a five-membered ring that includes a single oxygen atom, and pyridine, a heterocyclic compound with a six-membered ring containing one ...
Many simple aromatic rings have trivial names. They are usually found as substructures of more complex molecules ("substituted aromatics"). Typical simple aromatic compounds are benzene, indole, and pyridine. [1] [2] Simple aromatic rings can be heterocyclic if they contain non-carbon ring atoms, for example, oxygen, nitrogen, or sulfur.
In non-basic aromatic rings the lone pair of electrons of the nitrogen atom is delocalized and contributes to the aromatic pi electron system. In these compounds the nitrogen atom is connected to a hydrogen atom. Examples of non-basic nitrogen-containing aromatic rings are pyrrole and indole. Pyrrole contains a lone pair that is part of the pi ...
Pyrimidine (C 4 H 4 N 2; / p ɪ ˈ r ɪ. m ɪ ˌ d iː n, p aɪ ˈ r ɪ. m ɪ ˌ d iː n /) is an aromatic, heterocyclic, organic compound similar to pyridine (C 5 H 5 N). [3] One of the three diazines (six-membered heterocyclics with two nitrogen atoms in the ring), it has nitrogen atoms at positions 1 and 3 in the ring.
Get AOL Mail for FREE! Manage your email like never before with travel, photo & document views. Personalize your inbox with themes & tabs. You've Got Mail!
In organic chemistry, the Mannich reaction is a three-component organic reaction that involves the amino alkylation of an acidic proton next to a carbonyl (C=O) functional group by formaldehyde (H−CHO) and a primary or secondary amine (−NH 2) or ammonia (NH 3). [1] The final product is a β-amino-carbonyl compound also known as a Mannich base.