Carbon Disulfide → Methyl 2-(4-hydroxy-4-methyl-1,3-dithiolan-2-ylidene)-2-(4-methylthio-2-azetidinon-1-yl)acetate

HRID 980965Notes

Reaction equation

HRID 980965 reaction equation
C([Li])CCC.C[Si](C)(C)N[Si](C)(C)C.[CH3:15][O:16][C:17](=[O:26])[CH2:18][N:19]1[CH:22]([S:23][CH3:24])[CH2:21][C:20]1=[O:25].Br[CH2:28][C:29](=[O:31])[CH3:30].[C:32](=[S:34])=[S:33]>CCCCCC.O1CCCC1.C(O)(=O)C.C(OCC)(=O)C>[OH:31][C:29]1([CH3:30])[CH2:28][S:34][C:32](=[C:18]([N:19]2[CH:22]([S:23][CH3:24])[CH2:21][C:20]2=[O:25])[C:17]([O:16][CH3:15])=[O:26])[S:33]1

Participants

10

Reactant 5

HCID 6348Carbon DisulfideHCID 11715BromoacetoneHCID 13838HexamethyldisilazaneHCID 13556624Methyl (4-methylthio-2-oxoazetidin-1-yl)acetateHCID 178418339Butyllithium

Product 1

HCID 86741251Methyl 2-(4-hydroxy-4-methyl-1,3-dithiolan-2-ylidene)-2-(4-methylthio-2-azetidinon-1-yl)acetate

Reagents, catalysts & solvents 4

HCID 176Acetic AcidSolventHCID 8028TetrahydrofuranSolvent3×HCID 8058HexaneSolventHCID 8857Ethyl AcetateSolvent

Conditions

Temperature
-78 °C

Procedure

A solution of butyllithium in hexane (1.35 ml, 1.63 mmoles/ml) was added to a solution of hexamethyldisilazane (387 μl) in tetrahydrofuran (5 ml) at room temperature, and the mixture was stirred for 30 minutes. The solution was cooled to -78° C. and a solution of methyl(4-methylthio-2-azetidinon-1-yl)acetate (189 mg) in tetrahydrofuran (3 ml) was added thereto, after which the mixture was stirred for 10 minutes. Carbon disulphide (84 μl) was added to the solution and the mixture was stirred for 1 hour. A solution of bromoacetone (153 mg) in tetrahydrofuran (2 ml) was added to the resulting mixture, which was then stirred at -78° C. for 2 hours. The reaction mixture was then diluted with acetic acid (100 μl) and ethyl acetate, washed successively with an aqueous solution of sodium chloride, an aqueous solution of sodium bicarbonate and again an aqueous solution of sodium chloride, after which it was dried over anhydrous sodium sulphate. The solvent was distilled off under reduced pressure and the resulting residue was purified by preparative thin layer chromatography (eluent: a 2:1 by volume mixture of benzene and ethyl acetate), to give 290 mg of the desired product as a foamy substance.

Workup

  1. stirringafter which the mixture was stirred for 10 minutes
  2. stirringthe mixture was stirred for 1 hour
  3. stirringwas then stirred at -78° C. for 2 hours
  4. washwashed successively with an aqueous solution of sodium chloride
  5. dry with materialan aqueous solution of sodium bicarbonate and again an aqueous solution of sodium chloride, after which it was dried over anhydrous sodium sulphate
  6. distillationThe solvent was distilled off under reduced pressure
  7. customthe resulting residue was purified by preparative thin layer chromatography (eluent
  8. additiona 2:1 by volume mixture of benzene and ethyl acetate),

Sources & evidence

ORD record
ord-5c3479e8ab5d48148e3a06db83e01c3b
Source dataset
uspto-grants-1987_01
Patent number
US04639441

Reaction notes

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