반응 #1365702

ord-10b6824bcbc0490f9bb5c5e5887e5132

반응 조건

상세 조건
See reaction.notes.procedure_details.

후처리

  1. 1
    기타the temperature below 15° C
  2. 2
    workup.ADDITIONAfter addition
  3. 3
    기타reaction
  4. 4
    온도the reaction is heated to >40° C. for 2 hr
  5. 5
    온도The reaction is then cooled to <5° C.
  6. 6
    기타the temperature below 15° C
  7. 7
    기타The solid inorganic salts are removed by filtration
  8. 8
    세척These solids are washed with additional THF or toluene
  9. 9
    농축The filtered solution is then concentrated

실험 절차

To a cooled mixture of NaAlH4 (0.22 mol) in toluene is added LiCl (0.11 mol) in THF. Note: LiCl can be added to the reactor prior to the addition of NaAlH4 or after the addition of the substrate, (+/−)trans 3-ethoxycarbonyl-4-(4′-fluorophenyl)-N-methyl-piperidine-2,6-dione. Next, (+/−)trans 3-ethoxycarbonyl-4-(4′-fluorophenyl)-N-methyl-piperidine-2,6-dione (0.083 mol) is added in THF (65 ml) holding the temperature below 15° C. After addition is completed, reaction is allowed to warm to room temperature. After 30 minutes at room temperature, the reaction is heated to >40° C. for 2 hr. The reaction is then cooled to <5° C. and toluene (50 ml) is added. Water (9 ml) is then added slowly holding the temperature below 15° C. Additional H2O or aqueous NaOH is used as necessary. The solid inorganic salts are removed by filtration. These solids are washed with additional THF or toluene. The filtered solution is then concentrated to give (+/−) trans-4-(4′-fluorophenyl)-3-hydroxymethyl-N-methylpiperidine in essentially the same yield and similar impurity profile as with LiAlH4 as shown by HPLC analysis. The product can be recovered by standard procedures such as trituration with a less polar solvents.

출처

DOI: 10.6084/m9.figshare.5104873.v1특허: US06444190B2uspto-grants-2002_09