Abstract: The invention provides a block copolymerization polyimide composition comprising a block copolymerization polyimide obtained by heating a tetracarboxylic dianhydride and a diamine in at least one solvent selected from a ketone, an ether and an ester and in the presence of a catalyst generated from a lactone and a base, a positive type block copolymerization polyimide composition or ink containing a photooxygenation agent, and processes of producing them. The block copolymerization polyimide composition of the invention is never whitened even in the air.

Abstract: A process for preparing a 3-dihalobenzyl-2,4-quinazolinedione derivative represented by the formula (V): (wherein X1, X2, X3 are independently a halogen atom, and A is an alkylene group), which comprises: reacting a dihalobenzyl derivative represented by the formula (III): (wherein X2 and X3 are each as defined above, and L is an acid residue) with a 2,4-quinazolinedione derivative having a carboxyalkyl group represented by the formula (I): (wherein X1 and A are each as defined above) to selectively substitute a hydrogen atom of an imino group at the 3-position of the derivative (1). The above process enables the efficient preparation of the compounds of the above formula (V) useful as inhibitors against aldose reductases, makes it possible to secure the safety and hygiene of workers, and can facilitate waste disposal to reduce the expenses, thus being industrially extremely advantageous.