Synthesis and properties of 6-substituted benzo[a]pyrene derivatives

An improved route to benzo[a]pyrene-6-carbaldehyde is described, the nature of an impurity in this substance is discussed, the synthesis of a number of 6-substituted benzo[a]pyrene derivatives from the carbaldehyde is described, and the use of N-halogenosuccinimides for preparing 6-halogeno-derivatives of benzo[a]pyrene is examined. The fluorescence spectra and t.l.c. behaviour of the derivatives are described.