Methanol → 1-Tert-butyl 2-methyl 6-methoxypiperidine-1,2-dicarboxylate

HRID 722727Notes

Reaction equation

HRID 722727 reaction equation
[CH3:1][O:2][C:3]([CH:5]1[CH2:10][CH2:9][CH2:8][CH:7]([OH:11])[N:6]1[C:12]([O:14][C:15]([CH3:18])([CH3:17])[CH3:16])=[O:13])=[O:4].[CH3:19]O>>[CH3:1][O:2][C:3]([CH:5]1[CH2:10][CH2:9][CH2:8][CH:7]([O:11][CH3:19])[N:6]1[C:12]([O:14][C:15]([CH3:18])([CH3:17])[CH3:16])=[O:13])=[O:4]

Participants

3

Reactant 2

HCID 887MethanolHCID 696595626-hydroxy-piperidine-1,2-dicarboxylic Acid 1-tert-butyl Ester 2-methyl Ester

Product 1

HCID 670935071-Tert-butyl 2-methyl 6-methoxypiperidine-1,2-dicarboxylate

Procedure

The crude 6-hydroxy-piperidine-1,2-dicarboxylic acid 1-tert-butyl ester 2-methyl ester, 36, obtained in the previous step is dissolved in methanol (500 mL) and treated with Dowex-50 (1.0 g). After stirring at rt for 3 hr, the solution is filtered and concentrated in vacuo, and the residue is purified over silica (hexanes/ethyl acetate, 5:1) to afford 2.1 g of the desired product. 1H NMR (CDCl3) δ 5.43 (br s, 0.5H), 5.28 (br s, 0.5H), 4.88 (br s, 0.5H), 4.66 (br s, 0.5H), 3.73 (s, 3H), 3.33 (s, 3H), 2.32 (m, 1H), 1.87 (m, 2H), 1.70–1.40 (m, 3H), 1.51 (s, 9H).

Workup

  1. additiontreated with Dowex-50 (1.0 g)
  2. filtrationthe solution is filtered
  3. concentrationconcentrated in vacuo
  4. customthe residue is purified over silica (hexanes/ethyl acetate, 5:1)

Sources & evidence

ORD record
ord-78ebf86dab3b48f2a54fd3057fda501c
Source dataset
uspto-grants-2006_11
Patent number
US07138395B2

Reaction notes

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