4-Toluenesulfonyl chloride → 2-(4-fluorophenyl)-4-tosyloxy-5-[4-(methylsulfonyl)phenyl]-3(2H)-pyridazinone

Participants

Reaction Steps

2-(4-Fluorophenyl)-4-methoxy-5-bromo-3(2H)-pyridazinone (Example 194B) was converted into 2-(4-fluorophenyl)-4-methoxy-5-[4-(methylthio)phenyl]-3(2H)-pyridazinone according to the method of Example 194C followed by the oxidation method in Example 10. The methoxy compound was converted to the 2-(4-fluorophenyl)-4-hydroxy-5-[4-(methylsulfonyl)phenyl]-3(2H)-pyridazinone, by treatment with NaOH according to the procedure of Example 332. The hydroxy compound was treated with p-toluenesulfonyl chloride according to the procedure of Example 333, to furnish 2-(4-fluorophenyl)-5-[4-(methylsulfonyl)phenyl]-4-tosyloxy-3(2H)-pyridazinone.

Provenance & Evidence