DIBENZO-1,5-DIAZOCINE-2,6-DIONE, 2-IMINOINDOLIN-3-ONE AND N-(CARBAMOYLMETHYL)-AMINOBENZOIC ACID ESTER FROM AMINOBENZOIC ACID BY MULTICOMPONENT REACTIONS

Aminobenzoic acids show different types of multicomponent reactions wh en treated with a carbonylic component and an isocyanide in an alcohol ic solution. Anthranilic acid provides dibenzo-1,5-diazocine-2,6-dione derivatives by a double Ugi four component reaction (\-4CR) or depend ing on the reaction conditions the U-5C-4CR product, a N-(carbamoylmet hyl)anthranilic acid ester. Whereas anthranilic acid reacts hardly wit h ketones in that kind of multicomponent reaction Instead the preferre d reaction with isocyanides is the formation of 2-iminoindolin-3-ones. While 3-aminobenzoic acid shows no reaction, 4-aminobenzoic acid form s the U-5C-4CR product exclusively. (C) 1998 Elsevier Science Ltd. All rights reserved.