Hydrochloric Acid → 2-tert-butyl-5-chloro-4-methylpyridazin-3-(2H)-one

Participants

Reaction Steps

The resulting Grignard reagent was cooled to room temperature and was added dropwise over 20 minutes with 22.1 g (0.1 mol) of 2-tert.-butyl-4,5-dichloro-3(2H)-pyridazinone dissolved in 200 ml of dry toluene. After completion of adding, the reaction liquid was subjected to reaction for 1.5 hours at room temperature and then poured into a solution of 100 ml of conc. hydrochloric acid in 900 ml of ice-water to effect extraction. The resulting organic layer was then washed with 500 ml of 10% aqueous solution of sodium hydroxide and then with 500 ml of water, and dried over anhydrous sodium sulfate. The solvent was distilled off under reduced pressure to give 17.2 g of a crude product. The crude product was subjected to distillation (boiling point: 60° to 62° C./0.22 mmHg) and then column chromatography (silica gel; hexane:acetone=15:1) for separation and purification to give 4.5 g of 2-tert.-butyl-5-chloro-4-methyl-3(2H)-pyridazinone.

Provenance & Evidence