Sodium Carbonate → tert-Butyl 4-(2-nitrophenyl)-1,2,5,6-tetrahydropyridinecarboxylate

Temperature

90 °C

To a 100 mL round-bottomed flask equipped with stirring was added 2-nitrophenyl boronic acid (Combi-Blocks Chemical Company) (210 mg, 1.3 mmol), LiCl (Aldrich) (168 mg, 4 mmol), tetrakis(triphenyl-phosphine)palladium (O) (Strem Chemical Company) (69 mg, 0.06 mmol) and tert-butyl 4-[(trifluoromethyl)-sulfonyloxy]-1,2,5,6-tetrahydro-pyridinecarboxylate [prepared by the method of Wustrow, D. J. and Wise, L. D., Synthesis 1991, 993-995, from tert-butyl-4-oxopiperidine-1-carboxylate (Aldrich), LDA (Aldrich) and N-phenyltrifluoromethancsulfonimide (Aldrich)] (397 mg, 1.2 mmol) in DME (5 mL). The reaction mixture was purged with N2 and a 2 M soln of Na2CO3 (1.8 mL, 3.6 mmol) was introduced. After heating the mixture to 90° C. for 3 h, the reaction was cooled to 25° C. and diluted with EtOAc (15 mL). The organic layer was separated, washed with 10% Na2CO3, H2O and satd NaCl and dried over Na2SO4, filtered and concentrated in vacuo to afford a dark yellow oil. The crude material was purified by column chromatography (3:1 hexane:EtOAc) to give the title compound as a white solid (240 mg). MS (ESI, pos. ion) m/z: 305 (M+1). Calc'd for C16H20N2O4: 304.34.

1. customTo a 100 mL round-bottomed flask equipped
2. customprepared by the method of Wustrow, D
3. custom, Synthesis 1991, 993-995
4. customThe reaction mixture was purged with N2
5. temperaturethe reaction was cooled to 25° C.
6. customThe organic layer was separated
7. washwashed with 10% Na2CO3, H2O
8. dry with materialdried over Na2SO4
9. filtrationfiltered
10. concentrationconcentrated in vacuo
11. customto afford a dark yellow oil
12. customThe crude material was purified by column chromatography (3:1 hexane:EtOAc)

ORD record

ord-ca4b5f9ba6354ee08ad4f8a495404953

Source dataset

uspto-grants-2005_12

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US06977264B2