تفاعل #60665

ord-912ef1d36ddc417483676f3dfd4358d0

المذيبات

ظروف التفاعل

درجة الحرارة
85°CELSIUS
الظروف التفصيلية
See reaction.notes.procedure_details.

المعالجة

  1. 1
    درجة الحرارةby cooling to room temperature
  2. 2
    تركيزconcentrated under reduced pressure
  3. 3
    أخرىThe residue was partitioned between DCM (10 mL), aq Na2CO3 (10 mL, 2N solution) and conc NH4OH (0.6 mL)
  4. 4
    أخرىThe layers were separated
  5. 5
    استخلاصthe aqueous layer extracted with DCM (3×10 mL)
  6. 6
    تجفيفThe combined organic layers were dried (Na2SO4)
  7. 7
    تركيزconcentrated
  8. 8
    أخرىPurification by column chromatography (SiO2, Heptane/Ethylacetate/DCM 5:1:1)

الإجراء التجريبي

Pd(PPh3)4 (87 mg, 0.0075 mmol), LiCl (190 mg, 4.5 mmol), tert-butyl 4-{[(trifluoromethyl)sulfonyl]oxy}-3,6-dihydropyridine-1(2H)-carboxylate (0.50 g 1.5 mmol), 4-(trifluoromethoxy)phenylboronic acid (0.43 g, 2.1 mmol) and aq Na2CO3 (2 mL, 2N solution) were mixed in 5.2 mL DME and heated at 85° C. for 3 h followed by cooling to room temperature and concentrated under reduced pressure. The residue was partitioned between DCM (10 mL), aq Na2CO3 (10 mL, 2N solution) and conc NH4OH (0.6 mL). The layers were separated and the aqueous layer extracted with DCM (3×10 mL). The combined organic layers were dried (Na2SO4) and concentrated. Purification by column chromatography (SiO2, Heptane/Ethylacetate/DCM 5:1:1) gave tert-butyl 4-[4-(trifluoromethoxy)phenyl]-3,6-dihydropyridine-1(2H)-carboxylate (0.27 g, 52%). The product and 5% Pd/C (30 mg) was mixed in MeOH (3 mL) and stirred under H2 (1 atm) for 24 h. The mixture was filtered through Celite and concentrated to give tert-butyl 4-[4-(trifluoromethoxy)phenyl]piperidine-1-carboxylate (0.23 g, 86%). The crude product was dissolved in a mixture of TFA (2 mL) and DCM (4 mL) and stirred at RT for 2 h. The reaction mixture was concentrated and purified by preparative HPLC to give the title compound (0.14 g, 58%, three steps 26%).

المصدر

DOI: 10.6084/m9.figshare.5104873.v1براءة الاختراع: US07427631B2uspto-grants-2008_09