A 13, 15-diazasteroid system was synthesized from 2-(6-methoxynaphthyl) ethyl tosylate (steroidal segment of the A, B rings) and ethylene urea (steroidal segment of the D ring) in 24.3% overall yield. The tosylate formed a 1 : 1 adduct with ethylene urea in 44% yield, using 2 molar equivalents of ethylene urea in the presence of sodium hydride in benzene. The adduct was cyclized to 13, 15-diazasteroid hydrochloride in 69.7% yield by prolonged heating in the presence of phosphorus pentoxide in phosphorus oxychloride. The hydrochloride was neutralized to provide the 13, 15-diazasteroid in 79.1% yield by treatment with potassium hydroxide solution. The biological activity of the hydrochloride of the 13, 15-diazasteroid is now being examined.