Acetic Anhydride → 1-[4-(4-Aminophenyl)piperidin-1-yl]ethanone

A solution of 4-(4-nitro-phenyl)-3,6-dihydro-2H-pyridine-1-carboxylic acid tert-butyl ester (as prepared in the previous step, 304 mg, 1.00 mmol) in a 1:1 mixture of DCM/TFA (10 mL) was stirred at room temperature for 3 h and concentrated. The residue was dried in vacuo overnight, was taken up in CH2Cl2 (10 mL) and was cooled to 0° C. To this solution, Et3N (280 μL, 2 mmol) was added drop wise, followed by acetic anhydride (102 μL, 1 mmol). The resulting mixture was stirred at 0° C. for 1 h and allowed to warm to room temperature. The reaction mixture was washed with brine, and the organic layer was separated, dried and concentrated. The resulting product was reduced to obtain the title compound (143 mg, 65%) using a procedure similar to Example 4, step (d). 1H-NMR (CDCl3; 400 MHz): δ 6.97 (d, 2H, J=8.4 Hz), 6.64 (d, 2H, J=8.4 Hz), 4.75 (m, 1H), 3.93 (m, 1H), 3.13 (m, 3H), 2.66 (m, 2H), 2.12 (s, 3H), 1.84 (m, 2H), 1.57 (m, 2H).

1. concentrationconcentrated
2. customThe residue was dried in vacuo overnight
3. temperaturewas cooled to 0° C
4. stirringThe resulting mixture was stirred at 0° C. for 1 h
5. temperatureto warm to room temperature
6. washThe reaction mixture was washed with brine
7. customthe organic layer was separated
8. customdried
9. concentrationconcentrated

ORD record

ord-77a1a483912f425d885e4eb060a92023

Source dataset

uspto-grants-2015_01

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08933091B2