反应详情

5-Bromo-2-(1,4-dioxaspiro[4.5]dec-7-en-8-yl)-3-methylpyridine (21.1 g) described in Reference Example 105 was dissolved in concentrated hydrochloric acid (64.5 ml) and water (64.5 ml), and stirred at room temperature. After completion of the reaction, the reaction solution was ice-cooled, 10% sodium carbonate aqueous solution was added thereto to adjust the solution to pH 8, the precipitated solid was collected by filtration, washed with water, and then dried under air blow. The obtained solid was dissolved in ethanol, and the solvent was evaporated. This procedure was repeated twice, then to the obtained residue were added n-hexane and a small amount of ethyl acetate, washed, collected by filtration, and heat-dried in vacuo to give 4-(5-bromo-3-methylpyridin-2-yl)cyclohex-3-en-1-one (8.26 g) as a pale yellow solid. MS (ESI) m/z: 266, 268 (M+H)+.

1. customAfter completion of the reaction
2. temperaturecooled
3. filtrationthe precipitated solid was collected by filtration
4. washwashed with water
5. customdried under air blow
6. dissolutionThe obtained solid was dissolved in ethanol
7. customthe solvent was evaporated
8. additionto the obtained residue were added n-hexane
9. washa small amount of ethyl acetate, washed
10. filtrationcollected by filtration
11. customheat-dried in vacuo