Photo-additions of aromatic hydrocarbons—indene and naphthalene with acrylonitrile

Open Access
Publisher Website
Google Scholar
Abstract
The photolyses of indene and naphthalene with acrylonitrile have been studied, and the products characterized. Indene reacts with acrylonitrile when the hydrocarbon absorbs light, or when a triplet sensitizer (acetophenone) is absorbing. Photolysis under the former conditions in ethanol yields 2-(1-indenylpropionitrile) (70%), 2-(3-indenylpropionitrile) (10%), and 6-cyano-2,3-benzobicyclo[3,2,0]hept-2-ene (20%). Base-catalyzed isomerizations of the substituted indenes are reported. On sensitization, cis- and trans-isomers of 7-cyano-2,3-benzobicyclo[3,2,0]hept-2-ene are formed, with a minor amount of indene dimer. The former isomers can be equilibrated with strong base. Adducts of 1,1-dimethyl- and 1,1-diphenylindene with acrylonitrile are also described, and nuclear magnetic resonance data reported. Naphthalene adds acrylonitrile on photolysis in t-butyl alcohol (pyrex filter) to afford trans-8-cyano-2,3-benzobicyclo-[4,2,0]-octa-2,4-diene (90%) and 1- and 2-naphthyl-2-propionitrile (10%). Sensitization with acetophenone gave no detectable products. Irradiation of the major product at 253.7 mμ through Vycor gave naphthalene. The preparative value of these reactions is considered and possible mechanisms are proposed.

This publication has 0 references indexed in Scilit: