3-Nitrobenzaldehyde → 1-(3-Nitro-benzyl)-azetidine-3-carboxylic acid methyl ester

Temperature

40 °C

To a solution of amine INT 1 (6.00 g, 39.6 mmol) in CH2Cl2 (396 mL) and MeOH (50 mL) was added DIPEA (6.9 mL, 39.6 mmol). HOAc was added to adjust the pH of the solution to 4-5. 3-Nitrobenzaldehyde (6.58 g, 43.5 mmol) was added and the mixture was stirred at 40° C. for 1 hour. After cooling to room temperature, NaBH(OAc)3 (16.78 g, 79.2 mmol) was added and the mixture was stirred at room temperature overnight. The mixture was quenched with saturated aqueous NaHCO3. The aqueous layer was extracted with CH2Cl2 (2×). The combined organic layers were washed with brine, dried over MgSO4, filtered and concentrated. The residue was purified by flash chromatography on silica gel (CH2Cl2/MeOH) to afford INT 2.

1. temperatureAfter cooling to room temperature
2. stirringthe mixture was stirred at room temperature overnight
3. customThe mixture was quenched with saturated aqueous NaHCO3
4. extractionThe aqueous layer was extracted with CH2Cl2 (2×)
5. washThe combined organic layers were washed with brine
6. dry with materialdried over MgSO4
7. filtrationfiltered
8. concentrationconcentrated
9. customThe residue was purified by flash chromatography on silica gel (CH2Cl2/MeOH)
10. customto afford INT 2

ORD record

ord-262022c2e0ec42c8a1f6e018aeac4c82

Source dataset

uspto-grants-2014_07

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08791100B2