Process for the preparation of a 3(2H)-pyridazinone-4-substituted amino-5-choloro-derivative

Processes for the preparation of 5-chloro-4-{3-[N-[2-(3,4-dimethoxyphenyl)-ethyl]-N-methylamino]-propylamino}-3(2H)-pyridazinone of formula (I), which comprise: a1 reacting a compound of formula (II), wherein X stands for a leaving group, with N-methyl-homoveratryl amine of formula (VI), or a2 reacting a compound of formula (III), wherein R stands for lower alkanoyl, aroyl or aryl-(lower alkanoyl), adding a leaving group of formula X and reacting the obtained compound of formula (II) with the compound of formula (VI), or a3 reacting 4-(3-hydroxypropylamino)-3,5-dichloro-pyridazine of formula (IV) introducing a group of the formula R, reacting the obtained compound of formula (III) to produce a compound of formula (II), which is then reacted with a compound of formula (VI), or a4 reacting 3,4,5-trichloropyridazine of the formula (V) with 3-amino-1-propanol, reacting the obtained compound of formula (IV) adding a group of formula R, then reacting the obtained compound of formula (III) with an agent containing a leaving group of formula X, then reacting the obtained compound of formula (II) with a compound of formula (VI), or b1 removing the group of formula R from a compound of formula (IX), or b2 reacting the compound of formula (VIII) introducing a group of formula R and then removing R from the obtained compound of formula (IX), or b3 reacting a compound of formula (VII) with a compound of formula (VI), then reacting the obtained compound of formula (VIII) introducing a group of formula R and then removing R from the obtained compound of formula (IX), or b4 reacting a compound of formula (IV), adding a leaving group of formula X, reacting the obtained compound of formula (VII) with the compound of formula (VI), reacting the obtained compound of formula (VIII) introducing a group of formula R, then removing R from the obtained compound of formula (IX).