A process of production of trazodone or trazodone hydrochloride that comprises: (a) preparing an organic phase comprising trazodone in at least one organic solvent； (b) preparing an aqueous phase comprising at least one basic compound； (c) mixing said aqueous phase with said organic phase； (d) heating at a temperature of at least 40° C. for at least 30 minutes； (e) recovering said trazodone； and, optionally, (f) treating said trazodone with hydrochloric acid to obtain trazodone hydrochloride. Trazodone or trazodone hydrochloride comprising less than 15 ppm of alkylating substances, and a pharmaceutical composition comprising said trazodone hydrochloride.
