Benzoxazines are a group of

isomer In chemistry, isomers are molecules or polyatomic ions with identical molecular formulae – that is, same number of atoms of each element – but distinct arrangements of atoms in space. Isomerism is existence or possibility of isomers. Iso ...

ic bicyclic

heterocyclic A heterocyclic compound or ring structure is a cyclic compound that has atoms of at least two different elements as members of its ring(s). Heterocyclic chemistry is the branch of organic chemistry dealing with the synthesis, properties, and ...

chemical compounds that consist of a

benzene Benzene is an organic chemical compound with the molecular formula C6H6. The benzene molecule is composed of six carbon atoms joined in a planar ring with one hydrogen atom attached to each. Because it contains only carbon and hydrogen atoms, ...

ring fused to an

oxazine Oxazines are heterocyclic compounds containing one oxygen and one nitrogen atom in a doubly unsaturated six-membered ring. Isomers exist depending on the relative position of the heteroatoms and relative position of the double bonds. By extension ...

ring. The different isomers depend on the relative positions of the oxygen and nitrogen atoms in the oxazine ring, on the location of ring fusion, and on the position of the double bond in the oxazine ring. They have the molecular formula C₈H₇NO.

Preparation

1,3-Benzoxazines can be synthesized by the

Mannich reaction 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 () functional group by formaldehyde () and a primary or secondary amine () or ammonia (). ...

using a phenol, an amine, and formaldehyde.

Uses

Pharmaceutical drugs

Benzoxazine rings form the central chemical structure of a number of pharmaceutical drugs including, for example,

apararenone Apararenone (INN) (developmental code name MT-3995) is a nonsteroidal antimineralocorticoid which is under development by Mitsubishi Tanabe Pharma for the treatment of diabetic nephropathies and non-alcoholic steatohepatitis. It was also previou ...

elbasvir Elbasvir is a drug approved by the FDA in January 2016 for the treatment of hepatitis C. It was developed by Merck and completed Phase III trials, used in combination with the NS3/ 4A protease inhibitor grazoprevir under the trade name ''Zepat ...

, and

etifoxine Etifoxine (INN; also known as etafenoxine; trade name Stresam) is an anxiolytic and anticonvulsant drug developed by Hoechst in the 1960s. It is sold in approximately 40 countries for anxiety disorders, without the sedation and ataxia associate ...

Polymers

Polybenzoxazine Polybenzoxazines, also called benzoxazine resins, are cured polymerization products derived from benzoxazine monomers. Monomers Benzoxazines are bicyclic heterocyclic compounds containing one oxygen and one nitrogen atom in a doubly unsaturated ...

s, also called benzoxazine resins, are a class of polymers that are produced from the ring-opening polymerization of 3-phenyl-2,4-dihydro-1,3-benzoxazine monomers and its chemical

derivatives The derivative of a function is the rate of change of the function's output relative to its input value. Derivative may also refer to: In mathematics and economics * Brzozowski derivative in the theory of formal languages * Formal derivative, an ...

. The main applications of polybenzoxazines are as adhesives and in fiber-reinforced plastics.

References

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