What are fused heterocycles?
Another large class of heterocycles refers to those fused to benzene rings. For example, the fused benzene derivatives of pyridine, thiophene, pyrrole, and furan are quinoline, benzothiophene, indole, and benzofuran, respectively. The fusion of two benzene rings gives rise to a third large family of compounds.
Which of the following is an example of fused ring?
Example: Phenalene is considered as being composed of three benzene rings, each of which is ortho- and peri-fused to the other two. Any atom of a fused ring system which is common to two or more rings is termed a fusion atom.
Which of the following heterocyclic ring is most reactive -?
Explanation: Pyrrole is more reactive than furan and thiophene in electrophilic reactions.
How do you name heterocycles?
The name of the heterocyclic ring is chosen as the parent compound and the name of the fused ring is attached as a prefix. The prefix in such names has the ending ‘o’, i.e., benzo, naphtho and so on.
Which of following compound is called Benzopyrrol?
Indole, also called Benzopyrrole, a heterocyclic organic compound occurring in some flower oils, such as jasmine and orange blossom, in coal tar, and in fecal matter.
What are fused ring hydrocarbons?
Polycyclic aromatic hydrocarbons (PAHs) are sometimes referred to as polynuclear aromatic hydrocarbons (PNAs), condensed ring aromatics, or fused ring aromatics. They are a class of organic compounds consisting of two or more fused aromatic rings.
What fused bicyclic aromatic compound?
Naphthalene consists of two benzene rings that are fused together; the resulting molecule is still aromatic, and undergoes the reactions that are typical of benzene itself.
What is pyrimidine in chemistry?
Pyrimidines are 6-membered heterocyclic ring compounds composed of nitrogen. and carbon. They are present throughout nature in various forms and are the building blocks of numerous natural compounds from antibiotics to vitamins and liposacharides.
What does a pyrimidine structure look like?
The pyrimidines, cytosine and thymine are smaller structures with a single ring, while the purines, adenine and guanine, are larger and have a two-ring structure. E. The purines, adenine and cytosine, are large with two rings, while the pyrimidines, thymine and uracil, are small with one ring.
Why are heterocycles more reactive than benzene?
Since five-membered heterocycles with one heteroatom are with higher electron density on the carbon atoms and as such their reactivity towards electrophiles is higher than that of benzene.
Which heterocycles are aromatic?
Heterocycles – cyclic structures in which the ring atoms may include oxygen or nitrogen – can also be aromatic. Pyridine, for example, is an aromatic heterocycle.