反应详情

A mixture of 0.1 g (0.26 mmol) of the isoxazoline from Step E, 50 mg of 10% palladium on carbon catalyst and 48 mg (0.78 mmol) of boric acid in 3 ml of methanol and 0.3 ml of water was stirred under hydrogen (1 atmosphere) at room temperature for 2.5 hours. The mixture was filtered and the filtrate was poured into brine and extracted with ether. The ethereal extract was washed with 5% (w/v) aqueous sodium bicarbonate solution, dried (MgS04), filtered and evaporated to dryness to give 92 mg (0.23 mmol, 89%) as a pale yellow oil. nmr (CDCl3) δ: 2.30 (6H, a methyl singlet and a methyl doublet), 2.33 (3H, s), 2.35-2.5 (6H, m), 2.75-2.85 (2H, m), 3.30 (H, d), 3.70 (3H, s), 4.37 (H, m), 6.83 (H, bs), 6.95-7.1 (4H, m). IR (neat) 3450, 1710 cm-1.

1. filtrationThe mixture was filtered
2. additionthe filtrate was poured into brine
3. extractionextracted with ether
4. extractionThe ethereal extract
5. washwas washed with 5% (w/v) aqueous sodium bicarbonate solution
6. customdried (MgS04)
7. filtrationfiltered
8. customevaporated to dryness
9. customto give 92 mg (0.23 mmol, 89%) as a pale yellow oil