Reserpine → Methyl (3beta,16beta,17alpha,18beta,20alpha)-18-hydroxy-11,17-dimethoxyyohimban-16-carboxylate

HRID 2377020Notes

Reaction equation

HRID 2377020 reaction equation
[CH3:1][O:2][C:3]1[CH:4]=[CH:5][C:6]2[C:11]3[CH2:12][CH2:13][N:14]4[CH2:19][C@H:18]5[CH2:20][C@@H:21]([O:30]C(C6C=C(OC)C(OC)=C(OC)C=6)=O)[C@H:22]([O:28][CH3:29])[C@@H:23]([C:24]([O:26][CH3:27])=[O:25])[C@H:17]5[CH2:16][C@@H:15]4[C:10]=3[NH:9][C:7]=2[CH:8]=1.C[O-].[Na+]>CO>[CH3:29][O:28][C@@H:22]1[C@@H:23]([C:24]([O:26][CH3:27])=[O:25])[C@@H:17]2[C@@H:18]([CH2:19][N:14]3[C@H:15]([CH2:16]2)[C:10]2[NH:9][C:7]4[CH:8]=[C:3]([O:2][CH3:1])[CH:4]=[CH:5][C:6]=4[C:11]=2[CH2:12][CH2:13]3)[CH2:20][C@H:21]1[OH:30]

Participants

4

Reactant 2

HCID 5770ReserpineHCID 10942334Sodium Methoxide

Product 1

HCID 73532Methyl (3beta,16beta,17alpha,18beta,20alpha)-18-hydroxy-11,17-dimethoxyyohimban-16-carboxylateYield 995.2%

Reagents, catalysts & solvents 1

HCID 887MethanolSolvent

Procedure

A suspension of reserpine (1 g, 0.16 mmol) in a solution of sodium methoxide (0.150 g, 4.8 mmol) in methanol (50 ml) was refluxed until disappearance of the starting material (1 h), then cooled and concentrated under vacuum to one third of the volume. The solution was diluted with water (60 ml) and pH was adjusted to 1 with concentrated hydrochloric acid. The aqueous solution was then repeatedly washed with ethyl ether. The aqueous phase was then alkalinized with concentrated ammonia and repeatedly extracted with methylene chloride (4×30 ml). The combined organic phases were dried over sodium sulfate and concentrated under vacuum to give an amorphous residue (0.66 g), used for the following step without any further purification.

Workup

  1. temperaturewas refluxed until disappearance of the starting material (1 h)
  2. temperaturecooled
  3. concentrationconcentrated under vacuum to one third of the volume
  4. additionThe solution was diluted with water (60 ml) and pH
  5. washThe aqueous solution was then repeatedly washed with ethyl ether
  6. extractionrepeatedly extracted with methylene chloride (4×30 ml)
  7. dry with materialThe combined organic phases were dried over sodium sulfate
  8. concentrationconcentrated under vacuum

Sources & evidence

ORD record
ord-77d0239a35b041f5a83c71a604eabc36
Source dataset
uspto-grants-2008_12
Patent number
US07468438B2

Reaction notes

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