Abstract: A process for preparation of 10-oxo-10,11-dihydro-5H-dibenz[b,f]azepine-5-carboxamide (oxcarbazepine) via intermediate 10-methoxy-5H-dibenz[b,f]azepine-5-carbonyl chloride, comprising the steps: a) Preparation of an intermediate 10-methoxy-5H-dibenz[b,f]azepine-5 carbonyl, chloride from 10-methoxyiminostillbene using bis (trichloromethyl) carbonate (BTC) with organic base such as aliphatic or aromatic tertiary amines in organic solvent; b) Conversion of the intermediate to 10-methoxy-5H-dibenz[b,f]azepine-5-carboxamide using ammonia in organic solvent; c) Formation of oxcarbazepine from step (b) using Bronsted acid in an organic solvent at a temperature between 25° C.-80° C., preferably at 50° C. to 70° C.; and d) Isolation of oxcarbazepine.