Synthesis of 8,9-dialkoxybenzodiazepines and 7,8-dialkoxyisoquinolines

o-Aroylarylacetone type 1,5-diketone derivatives (5, 6) were synthesised from arylacetones (1) protected as 1,3-dioxolanes (4) through directed ortho lithiation followed by acylation with aroyl chlorides. 8,9-Dialkoxy-2,3-benzodiazepines 9 were obtained by cyclisation of diketones 6 with hydrazine. The reaction of diketones 6 with ammonia gave 7,8-dialkoxyisoquinolines 11. Reaction of ketals 5 with hydrazine hydrochloride and hydroxylamine hydrochloride afforded N-amino-7,8-dialkoxyisoquinolinium chlorides (10) and 7,8 -dialkoxyisoquinolinium oxides (12), respectively.