Acetic Anhydride → HCID 12795451, compound

HRID 1065834Notes

Reaction equation

HRID 1065834 reaction equation
[CH3:1][O:2][C:3](=[O:24])[C:4]([N:8]1[C@H:11]([S:12]SC2SC3C=CC=CC=3N=2)[CH2:10][C:9]1=[O:23])=[C:5]([CH3:7])[CH3:6].[C:25](OC(=O)C)(=[O:27])[CH3:26]>C(O)(=O)C.[Zn]>[CH3:1][O:2][C:3](=[O:24])[C:4]([N:8]1[C@H:11]([S:12][C:25](=[O:27])[CH3:26])[CH2:10][C:9]1=[O:23])=[C:5]([CH3:6])[CH3:7]

Participants

5

Reactant 2

HCID 7918Acetic AnhydrideHCID 12795449HCID 12795449, compound

Product 1

HCID 12795451HCID 12795451, compound

Reagents, catalysts & solvents 2

HCID 23994ZincCatalystHCID 176Acetic AcidSolvent

Procedure

1 g of zinc powder is added in portions over a period of one hour to a solution, stirred under nitrogen and in an ice bath, of 380 mg (1 mmol) of 2-[(4R)-4-(benzthiazol-2-yldithio)-2-oxoazetidin-1-yl]-3-methylcrotonic acid methyl ester in 3 ml of acetic anhydride and 5 ml of glacial acetic acid. The reaction mixture is further stirred for one hour at room temperature, filtered and concentrated in vacuo. The residue is taken up in methylene chloride and washed in succession with 25% aqueous ammonium chloride solution and aqueous sodium bicarbonate solution. The combined aqueous phases are reextracted with methylene chloride, all the methylene chloride phases are combined, dried with sodium sulphate and concentrated in vacuo. The residue is chromatographed over 40 g of silica gel (deactivated with 10% water) with toluene and toluene/ethyl acetate (19:1) and yields the optically pure title compound having a melting point of 78°-80°; [α]D20 =+149°±1° (c= 1.007%; in CHCl3).

Workup

  1. filtrationfiltered
  2. concentrationconcentrated in vacuo
  3. washwashed in succession with 25% aqueous ammonium chloride solution and aqueous sodium bicarbonate solution
  4. dry with materialdried with sodium sulphate
  5. concentrationconcentrated in vacuo
  6. customThe residue is chromatographed over 40 g of silica gel (deactivated with 10% water) with toluene and toluene/ethyl acetate (19:1)

Sources & evidence

ORD record
ord-5e630e514ad141679ad4b14a7c681e09
Source dataset
uspto-grants-1982_05
Patent number
US04331676

Reaction notes

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