ortho Amination of Naphthols by N-N Bond Cleavage of Hydrazines

Significance

Described is a simple thermal reaction of 2-naphthol, its analogues and quinoline derivatives 1 with N,N-disubstituted hydrazines 2 that leads to a general and efficient method for direct ortho amination to yield various α-aminated substituted naphthol and quinoline derivatives 3 and the corresponding secondary amines 4 in good to excellent yield. Only N-methyl-N-phenylhydrazine was employed on various naphthol analogues, whereas nine examples of N,N-disubstituted hydrazines were tested on 2-naphthol. The reaction proceeded well under solvent-free conditions. Reactions were also performed in methanol and chlorobenzene but required longer reaction times (15-60 h) for completion.