There is described a new polymorphic form of 4-(7-Hydroxy-2-isopropyl-4-oxo-4H-quinazolin- 3-yl)-benzonitrilehaving structural formula I(B) and to a method of preparing it. There isfurther a process or method for the manufacture of apharmaceutically active quinazolinone compounds of the formula (I), whereinthe symbols have the meanings given in the description,said process comprising reacting a compound of the formula (II), wherein R4*is R1*-C(=O)- wherein R1* is independently selectedfrom the group of meanings of R1 as defined for a compound of the formula (I)so that R1* and R1 are identical to or differentfrom each other, or R4*is especially H, and R1 and R3, R5 and R6 are asdefined for a compound of the formula (I), or a salt thereof,under simultaneous or sequential condensation and cyclisation conditions withan aniline compound of the formula (III), whereinR2 and m are as defined for a compound of the formula (I). Further reactionsand related embodiments are also claimed anddisclosed.
