Acetic Acid → HCID 68470916, compound

The acetyl-imine (Example 5, 9.37 g, 30.0 mmol) and methylboronic acid (1.796 g, 30.0 mmol) were dissolved into acetic acid (75 mL) and treated with NaBO3 (˜2.45 g, 30.0 mmol). After 40 minutes, more NaBO3 (˜2.45 g, 30.0 mmol) was added while the reaction vessel was in a water bath. More NaBO3 (2.45 g, 30.0 mmol) was added after a total of 80 minutes and again at 120 minutes (600 mg, 7.3 mmol). The mixture was stirred at room temperature overnight, transferred to a larger flask with an EtOAc rinse, and concentrated three times from toluene. The residue was mixed with water and basified with concentrated aqueous NH4OH, and then partitioned into 2:1 EtOAc/hexanes (150 mL). The aqueous phase was separated and extracted three times with more 2:1 EtOAc/hexanes. The combined organic phases were washed with a mixture of water (30 mL), concentrated aqueous NH4OH (5 mL) and brine (5 mL), then dried (Na2SO4), concentrated, and chromatographed on silica (15 to 30 to 50% EtOAc/hexanes) to give the titled compound. 1H NMR (400 MHz, CD3OD) δ ppm 4.77 (2H), 5.16 (1H), 5.32 (1H), 7.19 (1H), 7.23 (1H), 7.46 (1H); MS (ESI) 271 (M+H)+.

1. customwas in a water bath
2. waitagain at 120 minutes (600 mg, 7.3 mmol)
3. washrinse
4. concentrationconcentrated three times from toluene
5. additionThe residue was mixed with water and basified with concentrated aqueous NH4OH
6. custompartitioned into 2:1 EtOAc/hexanes (150 mL)
7. customThe aqueous phase was separated
8. extractionextracted three times with more 2:1 EtOAc/hexanes
9. washThe combined organic phases were washed with a mixture of water (30 mL), concentrated aqueous NH4OH (5 mL) and brine (5 mL)
10. dry with materialdried (Na2SO4)
11. concentrationconcentrated
12. customchromatographed on silica (15 to 30 to 50% EtOAc/hexanes)

ORD record

ord-1343c67495d94232b0cf3e9155ff89f2

Source dataset

uspto-grants-2013_06

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08470813B2