New efficient synthesis of isoquinoline-1,3(2H,4H)-diones and isoindolin-1-ones via sequential Ugi/cyclization reaction.

A new efficient synthesis of isoquinoline-1,3(2 H ,4 H )-diones or isoindolin-1-ones via sequential Ugi-4CR or Ugi-3CR/cyclization reaction was developed. α-Acylamino amides 5 , obtained from Ugi-4CR of methyl 2-formylbenzoate, amines, isocyanates and acids, cyclized to give isoquinoline-1,3(2 H ,4 H )-diones 6 in good yields in the presence of catalytic amount of sodium ethoxide. Ugi-3CR of methyl 2-formylbenzoate, amines and isocyanates in the presence of catalytic amount of H 3 PO 4 produced isoindolin-1-ones 7 directly in one-pot fashion. [ABSTRACT FROM AUTHOR]