A process for the preparation of 10-methoxycarbamazepine, an important intermediate in the preparation of 10-oxo-10, 11-dihydro-5H-dibenz(b,f)azepine-5-carboxamide(oxcarbazepine) from 10-methoxy-5H-dibenz(b,f)azepine(10-methoxyiminostilbene), is disclosed, which process comprises reacting 10-methoxyiminostilbene with cyanic acid (HOCN) in the presence of a mild acidic reagent in a solvent. Also disclosed is an improved method for the hydrolysis of 10-methoxycarbamazepine to oxcarbazepine, which method comprises carrying out the hydrolysis in a biphasic system chosen such that the oxcarbazepine is substantially insoluble in both phases, whereas the by-products or impurities are soluble in at least one of the phases. The oxcarbazepine thereby prepared is an anticonvulsant, and has been proposed for use as an anti-epileptical agent in the treatment of AIDS-related neural disorders, and for the treatment of Parkinson's disease and/or Parkinsonian syndromes.