Reaktion #975401

ord-4f6ba76cd4d3464c84504fcb41125b02

Lösungsmittel

Reaktionsbedingungen

Detaillierte Bedingungen
See reaction.notes.procedure_details.

Aufarbeitung

  1. 1
    SonstigeAfter 14 h of reaction at RT
  2. 2
    Sonstigethe solvent was evaporated
  3. 3
    Sonstigeto give an oil
  4. 4
    SonstigePurification by chromatography (SiO2)

Vorschrift

To a solution of a 55/45 diastereoisomeric mixture of pentafluorophenyl (2S)-2-[(4S)-2,2-dimethyl-5-oxo-1,3-dioxolan-4-yl]-4-methylpentanoate and pentafluorophenyl (2R)-2-[(4S)-2,2-dimethyl-5-oxo-1,3-dioxolan-4-yl]-4-methylpentanoate (Intermediate 1, 792.6 mg; 2.0 mmol; 1.0 eq.) in DMF (15 mL) was added 1-(2-pyridyl)piperazine (326.5 mg; 2.0 mmol; 1.0 eq.). After 14 h of reaction at RT, the solvent was evaporated to give an oil. Purification by chromatography (SiO2) gave the title compound as a colorless oil (as a mixture of 2 diastereoisomers 50/50). This product was dissolved on iPrOH (10 mL) at kept at −20° C. for 48 h. The supernatant was collected and evaporated to give a colorless oil (301 mg, 40%, single diastereoisomer). M+(ESI): 3763. HPLC (Condition A): Rt: 5.0 min (HPLC purity: 77.1%). 1H NMR (CDCl3, 300 MHz) δ 822 (d, J=4.2 Hz, 1H), 7.58-7.47 (m, 1H), 6.74-6.63 (m, 2H), 4.54 (d, J=6.0 Hz, 1H), 3.88-3.41 (m, 8H), 3.33-322 (m, 1H), 1.89-1.62 (m, 3H), 1.61 (s, 3H), 1.55 (s, 3H), 0.99-0.88 (m, 6H).

Quelle

DOI: 10.6084/m9.figshare.5104873.v1Patent: US08247437B2uspto-grants-2012_08