申请人:Hoechst Aktiengesellschaft
公开号:US05710319A1
公开(公告)日:1998-01-20
The invention relates to a process for the preparation of quinazoline-2,4-diones of the formula (I) ##STR1## in which R.sup.1 is (C.sub.1 -C.sub.12)alkyl, (C.sub.3 -C.sub.8)cycloalkyl or (C.sub.7 -C.sub.10)aralkyl, it being possible for the aryl group to be substituted by one or more halogen atoms, and R.sup.2, R.sup.3, R.sup.4 and R.sup.5, independently of one another, are halogen, alkyl, alkoxy or hydrogen, which comprises reacting anthranilic acid esters of the formula (II) ##STR2## in which R is (C.sub.1 -C.sub.10)alkyl and R.sup.2 to R.sup.5 are as defined above, with isocyanates R.sup.1 -.dbd.C.dbd.O in an aprotic reaction medium to give carbamoylanthranilic acid esters of the formula (III) ##STR3## in which R, R.sup.1 to R.sup.5 are as defined above, and cyclizing these products in the presence of alkali metal alcoholates, alkali metal amides, alkali metal hydrides, alkaline earth metal alcoholates, alkaline earth metal amides, alkaline earth metal hydrides or tetraalkylammonium hydroxides.
本发明涉及一种制备公式(I)的喹唑啉-2,4-二酮的过程:
其中R1是(C1-C12)烷基,(C3-C8)环烷基或(C7-C10)芳基烷基,芳基可以被一个或多个卤素原子取代,而R2,R3,R4和R5是独立的卤素,烷基,烷氧基或氢。该过程包括将公式(II)的蒽酰氨酸酯与异氰酸酯R1-C=O在非质子溶剂反应介质中反应,以得到公式(III)的氨基甲酰蒽酰氨酸酯:
其中R,R1至R5如上定义,并在碱金属醇盐,碱金属氨基盐,碱金属氢化物,碱土金属醇盐,碱土金属氨基盐,碱土金属氢化物或四烷基铵氢氧化物的存在下环化这些产物。