Nitrophenylcarbenes. Part II. The generation and reactions of 4-nitrophenylcarbene. Nature of the reactions of 4-nitrobenzyl derivatives with sodium hydroxide

Abstract

4-Nitrophenylcarbene, generated by the catalytic and photolytic decomposition of α-diazo-4-nitrotoluene, can be trapped by 2-butene. When produced photolytically the carbene adds non-stereospecifically to cis- and trans-but-2-enes to give a mixture of cyclopropane adducts, indicating a reaction of a triplet state. The reactions of sodium hydroxide with 4-nitrobenzyl chloride and dimethyl-4-nitrobenzylsulphonium ion were found to be sensitive to air. Reactions under nitrogen do not give 4,4′-dinitrostilbene as the sole product and bis-(4-nitrophenyl)acetylene (10%) could also be isolated. α-Elimination in these reactions is unlikely and alternative mechanisms are discussed.