The present invention concerns a new process for the synthesis of aminaphtone, which makes use of non-toxic solvents and reagents, under mild reaction and temperature conditions. The aminaphtone obtained with the method of the present invention also has a purity of at least 98% in weight. The method comprises the following steps: a) epoxidating menadione 1 to provide epoxide 2, b) acidifying epoxide 2 to provide hydroxynaphthoquinone 3, c) esterifying between hydroxynaphthoquinone 3 and 4-aminobenzoyl chloride to obtain compound 4, and d) reducing compound 4 in the presence of a reducing agent in water to obtain aminaphtone.