Activity of β-lapachone derivatives against rifampicin-susceptible and -resistant strains of Mycobacterium tuberculosis.

The increase of incidence of tuberculosis (TB) with resistant strains and HIV co-infection has reinforced the necessity of developing new drugs for its treatment. The reaction of naphthoquinones with aromatic or aliphatic aldehydes in the presence of ammonium acetate led to the synthesis of the three β-lapachone derivatives (naphthoimidazoles) that were tested in this study. Phenazines were prepared by the reaction of the respective naphtoquinone with o-phenylenediamine in acetic acid under reflux.

1,4- Addition of diazomethane to a heterodiene: a direct preparation of the oxazolic ring.

The reaction of naphthoquinone-oximes (3) and (4) with diazomethane yields directly, in one step, the oxazoles (5) and (6), respectively.