N,N-Dimethylcarbamoylation of the anilinic nitrogen atom N(1) on the Spiro 7-azaindoline consists of two steps. The first step is N,N-dimethylcarbamoylation of the pyridyl nitrogen atom N(7), leading to the formation of an isolable intermediate. The second step is intermolecular migration of the N,N-dimethylcarbamoyl group from the pyridyl nitrogen atom N(7) to the anilinic nitrogen atom N(1). We accomplished optimization of the reaction conditions based on the revealed reaction mechanism and a large scale synthesis of compound 3 in quantitative yield. (c) 2013 Elsevier Ltd. All rights reserved.