4-Methoxybenzylamine → 1-(4-Methoxy-benzyl)-4-(4-nitro-phenyl)-piperidine-2,6-dione

Temperature

85 °C

A solution of 12.6 g (53.6 mmol) of 4-(4-nitro-phenyl)-dihydro-pyran-2,6-dione (as prepared in the previous step) in THF (160 mL) was treated with 9.04 mL (6.96 mmol) of 4-methoxy-benzylamine at RT for 2 h. Solvents were evaporated in vacuo. The residue was dissolved in 1.0 N HCl (200 mL) and extracted with EtOAc (2×250 mL). The combined organic layers were washed with water (1×200 mL), dried (MgSO4) and concentrated in vacuo. The residue was treated with acetic anhydride (200 mL) and triethylamine (30 mL), and heated to 85° C. for 1.5 h. The mixture was concentrated in vacuo, treated with 1.0 N HCl (200 mL), and extracted with EtOAc (3×200 mL). The combined organic layers were washed with saturated aqueous NaHCO3 (1×200 mL) and water (1×200 mL), dried (MgSO4), and concentrated in vacuo. The solid was triturated with hexane using sonication, filtered and air-dried to afford 16.5 g (87%) of the title compound as light tan solid: Mass spectrum (ESI, m/z): Calcd. for C19H21N2O, 325.1 (M−OCH3+2H). found 325.0.

1. customSolvents were evaporated in vacuo
2. dissolutionThe residue was dissolved in 1.0 N HCl (200 mL)
3. extractionextracted with EtOAc (2×250 mL)
4. washThe combined organic layers were washed with water (1×200 mL)
5. dry with materialdried (MgSO4)
6. concentrationconcentrated in vacuo
7. additionThe residue was treated with acetic anhydride (200 mL) and triethylamine (30 mL)
8. concentrationThe mixture was concentrated in vacuo
9. additiontreated with 1.0 N HCl (200 mL)
10. extractionextracted with EtOAc (3×200 mL)
11. washThe combined organic layers were washed with saturated aqueous NaHCO3 (1×200 mL) and water (1×200 mL)
12. dry with materialdried (MgSO4)
13. concentrationconcentrated in vacuo
14. customThe solid was triturated with hexane using sonication
15. filtrationfiltered
16. customair-dried

ORD record

ord-5317e449ec0b46d1bd95add5da555706

Source dataset

uspto-grants-2016_03

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US09296726B2