Improved Method for Microwave-Assisted Synthesis of Benzodiazepine-2,5-diones from Isatoic Anhydrides Mediated by Glacial Acetic Acid

• Autor(a) principal: Cruz,Armando De La
• Data de Publicação: 2018
• Outros Autores: Vega-Acevedo,Carlos Alejandro, Rivero,Ignacio A., Chávez,Daniel
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Journal of the Brazilian Chemical Society (Online)
• Texto Completo: http://old.scielo.br/scielo.php?script=sci_arttext&pid=S0103-50532018000801607
• topic: benzodiazepin-2,5-diones; 7-iodobenzodiazepin-2,5-diones; microwave irradiation; isatoic anhydride; 6-iodoisatoic anhydride

An improved and simpler method for the synthesis of benzodiazepin-2,5-diones and 7-iodobenzodiazepin-2,5-diones catalyzed by glacial acetic acid using isatoic anhydride and 6-iodoisatoic anhydride, respectively, as starting materials is reported. The target products were achieved in good yields (up to 71%) using microwave irradiation as the activating mode of reaction in the presence of acetic acid instead of the traditional polar aprotic solvents as dimethylformamide (DMF), dimethyl sulfoxide (DMSO) or dimethylacetamide (DMAC). Moreover, relatively simple purification workup is required. The optimal temperature to obtain the benzodiazepin-2,5-dione derivatives was 130 ºC, while the best irradiation time was 3 min. In addition, the methodology for the selective preparation of 6-iodoisatoic anhydride with an overall yield of 62% is presented.