反应详情

4N Aqueous solution of sodium hydroxide (5 ml) and water (5 ml) were added to a solution of 8-(5-bromopyridin-2-yl)-1,4-dioxaspiro[4,5]decane-8-carboxylic acid ethyl ester (1.0 g) described in Reference Example 81(2) in methanol (10 ml) and tetrahydrofuran (10 ml), and stirred at 80° C. for eight hours. After completion of the reaction, the organic solvent was evaporated and the aqueous layer was washed with diethyl ether. Concentrated hydrochloric acid was added to the aqueous layer under ice cooling, pH was adjusted to 4-5, and extracted with chloroform. The organic layer was dried over anhydrous sodium sulfate and concentrated to give 8-(5-bromopyridin-2-yl)-1,4-dioxaspiro[4,5]decane-8-carboxylic acid (864 mg) as a colorless solid.

1. customAfter completion of the reaction
2. customthe organic solvent was evaporated
3. washthe aqueous layer was washed with diethyl ether
4. additionConcentrated hydrochloric acid was added to the aqueous layer under ice cooling
5. extractionextracted with chloroform
6. dry with materialThe organic layer was dried over anhydrous sodium sulfate
7. concentrationconcentrated