| abstract |
"PROCESSES FOR THE PREPARATION OF PIRAZOLOPYRIMIDINONES". A process for the production of a compound of formula I is provided: wherein A, A ^ 1 ^, R ^ 2 ^, R ^ 3 ^ and R ^ 4 ^ have the meanings given in the description, which process comprises the reaction. of a compound of formula (II) wherein R 4 is a group which may be substituted by an aminopyrazole with a compound of formula (III) |