反应详情

温度

-78 °C

To a solution of 2-Bromo-3-dimethylamino-5,5,8,8-tetramethyl-5,6,7,8-tetrahydronaphthalene (67.08 g, 0.216 mol) in 300 mL of anhydrous THF at −78° C. was added dropwise at −78° C. a 1.6 molar solution of n-butyl lithium (1.6 M, 203 mL, 1.5 eq.) over a period of 30 minutes. The reaction was stirred for 10 min. at −78° C. and 150 ml of tri(iso-propyl) borate (3 eq.) was added dropwise over 0.5 hr. The mixture was allowed to warm to room temperature overnight. The resulting thick mixture was diluted with THF, cooled to 0° C. and 1N hydrochloric acid was added. The reaction was stirred for 0.5 hr at room temperature. The resulting layers were separated and the aqueous phase was washed with EtOAc. The aqueous layer was neutralized to pH 7 to give a precipitate that was extracted with dichloromethane. The aqueous phase was saturated with sodium chloride and extraction was continued. The combined organic layers were dried over sodium sulfate, filtered and evaporated to yield an oil which slowly crystallized on standing. The solid was collected by filtration, washed with hexane and dried to afford 23.00 g of (3-dimethylamino-5,5,8,8-tetramethyl-5,6,7,8-tetrahydronaphthalen-2-yl) boronic acid (39%). 1H-NMR (300 MHz, DMSO-d6): 1.20 (s, 6 H), 1.23 (s, 6 H), 1.60 (s, 4 H), 2.62 (s, 6 H), 7.25 (s, 1 H), 7.64 (s, 1 H), 9.14 (s, 2 H).

1. temperatureto warm to room temperature overnight
2. temperaturecooled to 0° C.
3. stirringThe reaction was stirred for 0.5 hr at room temperature
4. customThe resulting layers were separated
5. washthe aqueous phase was washed with EtOAc
6. customto give a precipitate that
7. extractionwas extracted with dichloromethane
8. extractionThe aqueous phase was saturated with sodium chloride and extraction
9. dry with materialThe combined organic layers were dried over sodium sulfate
10. filtrationfiltered
11. customevaporated
12. customto yield an oil which
13. customslowly crystallized
14. filtrationThe solid was collected by filtration
15. washwashed with hexane
16. customdried