p-Toluenesulfonic acid → HCID 13373610, compound

HRID 2417768Notes

Reaction equation

HRID 2417768 reaction equation
[CH3:1][O:2][C:3](=[O:20])[C@@H:4]1[CH2:8][C:7](=O)[CH2:6][N:5]1[C:10]([O:12][CH2:13][C:14]1[CH:19]=[CH:18][CH:17]=[CH:16][CH:15]=1)=[O:11].C1(C)C=CC(S(O)(=O)=O)=CC=1.[CH2:32]([SH:35])[CH2:33][SH:34].C(=O)(O)[O-].[Na+]>C(O)(=O)C>[CH3:1][O:2][C:3]([C@@H:4]1[CH2:8][C:7]2([S:35][CH2:32][CH2:33][S:34]2)[CH2:6][N:5]1[C:10]([O:12][CH2:13][C:14]1[CH:19]=[CH:18][CH:17]=[CH:16][CH:15]=1)=[O:11])=[O:20]

Participants

6

Reactant 4

HCID 6101p-Toluenesulfonic acidHCID 109021,2-EthanedithiolHCID 516892Sodium BicarbonateHCID 115942881-Benzyl 2-methyl (2S)-4-oxopyrrolidine-1,2-dicarboxylate

Product 1

HCID 13373610HCID 13373610, compound

Reagents, catalysts & solvents 1

HCID 176Acetic AcidSolvent

Procedure

Dissolve 7.0 g of 1-benzyloxycarbonyl-4-keto-(S)-proline methyl ester in 75 ml of glacial acetic acid. Add 0.7 g of p-toluenesulfonic acid and 2.8 g of 1,2-ethanedithiol and heat under reflux with stirring for eighteen hours. Add the reaction mixture to saturated sodium bicarbonate solution and extract with ethyl acetate. Dry the organic layer over magnesium sulfate and concentrate it. Place the residue on a column of silica gel (300 g, 60-200 mesh) and elute with hexane:ethyl acetate (1:1) to give 7-benzyloxycarbonyl-1,4-dithia-7-azaspiro-[4.4]nonane-8(S)-carboxylic acid methylester, a yellow oil having [α]D26 -12.6° (dioxane).

Workup

  1. temperatureheat
  2. temperatureunder reflux
  3. extractionextract with ethyl acetate
  4. dry with materialDry the organic layer over magnesium sulfate
  5. concentrationconcentrate it
  6. washelute with hexane:ethyl acetate (1:1)

Sources & evidence

ORD record
ord-8fc17723cfe94c3688b50ae9719afe57
Source dataset
uspto-grants-1984_09
Patent number
US04470972

Reaction notes

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