反应详情

To a suspension of 4-methoxybenzaldehyde (10.0 g, 73.4 mmol) and 1,2,4-thiadiazol-5-amine (7.40 g, 73.4 mmol) in dichloromethane (200 mL) was added chlorotitanium triisopropoxide (28.6 g, 110 mmol) portionwise over 5 min. After stirring for 3 hours, sodium triacetoxyborohydride (38.9 g, 184 mmol) was added portionwise at 0° C. and allowed to stir for additional 1 hour. The reaction was cooled in an ice and water mixture, quenched with saturated NaHCO3 solution (300 mL) and extracted with dichloromethane (2×300 mL). The organic layer was separated, dried over Na2SO4, filtered and concentrated to obtain the product, which was purified by column chromatography using silica gel (100 to 200 mesh) and 0 to 30% ethyl acetate in hexane to give 5.5 g of as an off-white solid. MS (ESI, positive) m/z: 222.1; 1H NMR (400 MHz, DMSO-d6) δ 8.89 (s, 1H), 7.92 (s, 1H), 7.27 (d, J=8.5 Hz, 2H), 6.91 (d, J=8.5 Hz, 2H), 4.42 (d, J=5.4 Hz, 2H), 3.73 (s, 3H).

1. stirringto stir for additional 1 hour
2. customquenched with saturated NaHCO3 solution (300 mL)
3. extractionextracted with dichloromethane (2×300 mL)
4. customThe organic layer was separated
5. dry with materialdried over Na2SO4
6. filtrationfiltered
7. concentrationconcentrated
8. customto obtain the product, which
9. customwas purified by column chromatography
10. customto give 5.5 g of as an off-white solid