反应详情

温度

5 °C

To a solution of ethyl 6-difluoromethoxy-4-oxo-3,4-dihydrobenzo[4,5]furo[2,3-d]pyridazine-9-carboxylate (from step 6 of example 4) (261 mg, 0.803 mmol) in n,n-dimethyl formamide, sodium hydride (33 mg, 0.803 mmol) was added at 20-30° C. under nitrogen. Ethyl bromide (95.4 mg, 0.88 mmol) was added to the reaction mixture. Progress of reaction was monitored by TLC. At the end, reaction mixture was cooled to 0-10° C. Water (100 ml) was added dropwise to the reaction mixture at 0-10° C. and acidified with dilute hydrochloric acid. The precipitate obtained was filtered and dried in oven. It was purified by silica gel column chromatography using 10% ethyl acetate in chloroform. White colored solid (130 mg) was obtained.

1. customProgress of reaction
2. customAt the end, reaction mixture
3. customThe precipitate obtained
4. filtrationwas filtered
5. customdried in oven
6. customIt was purified by silica gel column chromatography