Reaktion #335383

ord-7210503a5ef7460a8a1b376243299de6

Reaktionsbedingungen

Temperatur
25°CELSIUS
Detaillierte Bedingungen
See reaction.notes.procedure_details.

Aufarbeitung

  1. 1
    workup.STIRRINGto stir at 25° C. overnight
  2. 2
    FiltrationThe mixture was worked-up by filtration through a coarse sintered glass funnel
  3. 3
    workup.ADDITIONcontaining
  4. 4
    SonstigeThe solvent was removed by rotary evaporation
  5. 5
    Sonstigeto afford a smelly yellow oil
  6. 6
    SonstigePurification by flash chromatography on silica gel (EM silica gel 60, 0.040-0.063 partical size, 230-400 Mesh, column size: 10 cm diameter×30 cm length)

Vorschrift

To a solution of 60% sodium hydride in mineral oil (7.0 g, 0.20 mol) and acetonitrile (200 mL) under a nitrogen atmosphere was added dropwise a solution of 2,6-di-t-butyl-4-mercaptophenol (A) (53.7 g, 0.23 mol, 90%) in acetonitrile (100 mL) over a 1 h period. The reaction mixture was stirred at 25° C. for an additional hour to ensure complete anion generation. To the mercaptophenol anion was added a solution of methyl (2S)-2-(phenylsulfonyloxy)propanate (50 g, 0.20 mol, 12) in acetonitrile (100 mL) dropwise over a 1 h period. Upon addition of methyl (2S)-2-(phenylsulfonyloxy)propanate a white precipitate was observed. The reaction mixture was allowed to stir at 25° C. overnight. The mixture was worked-up by filtration through a coarse sintered glass funnel containing was Celite®. The solvent was removed by rotary evaporation to afford a smelly yellow oil. Purification by flash chromatography on silica gel (EM silica gel 60, 0.040-0.063 partical size, 230-400 Mesh, column size: 10 cm diameter×30 cm length) using hexane and ethyl acetate (9:1) afforded 51.3 g (81%) of methyl (2R)-2-(3,5-di-t-butyl-4-hydroxyphenyl)thiopropanoate (31) as a thick oil: 1H NMR (CDCl3) δ1.42-1.45 (m, 21 H), 3.60-3.68 (q, J=7.2 Hz, 1 H), 3.67 (s, 3 H), 5.33 (s, --OH, 1 H), 7.29 (s, 2 H); 13C NMR (CDCl3) δ173.3, 154.6, 136.6, 131.8, 122.0, 52.0, 46.0, 34.3, 30.2, 17.4; IR (neat) 3635 (s), 2958 (vs), 2875 (s), 1737 (vs), 1426 (vs), 1237 (vs), 1160 (vs), 855 (w), 774 (w) cm-1.

Quelle

DOI: 10.6084/m9.figshare.5104873.v1Patent: US05208345uspto-grants-1993_05