3-Nitrobenzenesulfonic acid → 6-[5-(Imidazol-1-yl-methyl)-thien-2-yl]-3(2H)-pyridazinone

Participants

Reaction Steps

20 g of 4.5-dihydro-6-[5-(imidazol-1-yl-methyl)-thien-2-yl]-3(2H)-pyridazinone (EP No. 71 059, Example 1) are stirred under reflux together with 19.5 g of the sodium salt of 3-nitrobenzenesulfonic acid and 13.5 g of sodium hydroxide in b 250 ml of water for 1 hour. Thereafter, while the solution is still hot, acetic acid are added until pH 6.9. The solid material precipitated after cooling is filtered of with suction, washed with water and dried.

Provenance & Evidence