Benzocyclobutadiene

{{distinguish|benzocyclobutene}}

{{Chembox

| verifiedrevid = 459537872

| ImageFile =Benzocyclobutadiene.svg

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| PIN = Bicyclo[4.2.0]octa-1,3,5,7-tetraene

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|Section1={{Chembox Identifiers

| CASNo_Ref = {{cascite|correct|??}}

| CASNo = 4026-23-7

| UNII_Ref = {{fdacite|correct|FDA}}

| UNII = T7CEM83V4M

| SMILES = C12=CC=CC=C1C=C2

| PubChem = 77987

| ChemSpiderID_Ref = {{chemspidercite|correct|chemspider}}

| ChemSpiderID = 70373

| InChI = 1/C8H6/c1-2-4-8-6-5-7(8)3-1/h1-6H

| InChIKey = WHEATZOONURNGF-UHFFFAOYAK

| StdInChI_Ref = {{stdinchicite|correct|chemspider}}

| StdInChI = 1S/C8H6/c1-2-4-8-6-5-7(8)3-1/h1-6H

| StdInChIKey_Ref = {{stdinchicite|correct|chemspider}}

| StdInChIKey = WHEATZOONURNGF-UHFFFAOYSA-N}}

|Section2={{Chembox Properties

| C=8 | H=6

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|Section3={{Chembox Hazards

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Benzocyclobutadiene is the simplest polycyclic hydrocarbon, being composed of an aromatic benzene ring fused to an anti-aromatic cyclobutadiene ring. It has chemical formula {{chem2|C8H6}}. Though the benzene ring is stabilized by aromaticity, the cyclobutadiene portion has a destabilizing effect. This results into it being a non-aromatic compound - neither behaving as aromatic nor an antiaromatic one.Observation of benzocyclobutadiene by flow nuclear magnetic resonance https://doi.org/10.1021/ja00168a059 For this reason, benzocyclobutadiene will readily dimerize or polymerize and it reacts as a dienophile in Diels-Alder reactions.{{cite book |author1= Carey, Francis A. |author2=Sundberg, Richard J. | date = 1984 | title = Advanced Organic Chemistry Part A Structure and Mechanisms | edition = 2nd | location = New York, NY | publisher = Plenum Press | isbn = 0-306-41198-9}}

Benzocyclobutadiene is used in the production of the pharmaceutical drug naflocort.{{cn|date=January 2017}}