New O-aminonitriles (enaminonitriles) namely, pyrimido[1,6-a] indole were prepared by addition of 2-dicyanome thylidinoindoline-obtained from oxindole- to various isothiocyanates. The obtained enaminonitriles were acylated using chloroacetylchloride yielding methylchloride derivatives of the condensed pyrimidines, pyrimido (4,5 :4,5] pyrimido[1,6-a] indole. The chlorine atom was substituted by different amines or condensed with thiourea and the formed salts were hydrolyzed to give mercaptoalkyl compounds. Some of the prepared compounds were tested for their analgetic activities.