Dimethyl Sulfoxide → HCID 15229884, compound

Temperature

-78 °C

A solution prepared by the sequential addition of oxalyl chloride (2.9 g, 23 mmol) and dimethyl sulfoxide (3.7 g, 47 mmol) to methylene chloride which had been cooled to -78° C. was allowed to stir for 12 minutes. A solution of 6-hydroxy-2,5,7,8-tetramethyl-3,4-dihydro-2H-benzo[1,2-b]pyran-2-yl methanol (4.0 g, 18 mmol) in 50 mL methylene chloride was then added dropwise to the reaction mixture. After stirring for 40 min., triethylamine (7.3 g, 72.6 mmol) was added dropwise over 5 min. The reaction mixture was stirred at -78° C. for 15 min and then at ambient temperature for 30 min. The reaction mixture was diluted with methylene chloride (100 mL). The resulting solution was washed (water 100 mL, brine 100 mL, water 100 mL), dried (magnesium sulfate), and concentrated under reduced pressure to give a yellow oil. The oil was chromatographed (SiO2, 200 g, ethyl acetate-hexane, 1:9) to give 6-hydroxy-2,5,7,8-tetramethyl-3,4-dihydro-2H-benzo[1,2-b]pyran-2-yl methanal as a white solid (3.0 g, 70% yield).

1. stirringAfter stirring for 40 min.
2. stirringThe reaction mixture was stirred at -78° C. for 15 min
3. waitat ambient temperature for 30 min
4. washThe resulting solution was washed (water 100 mL, brine 100 mL, water 100 mL)
5. dry with materialdried (magnesium sulfate)
6. concentrationconcentrated under reduced pressure
7. customto give a yellow oil
8. customThe oil was chromatographed (SiO2, 200 g, ethyl acetate-hexane, 1:9)

ORD record

ord-28b946051d254dc287fe4d24c3494373

Source dataset

uspto-grants-1998_12

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US05846988