Reaktion #62544

Reaktionsgleichung

4-Bromomethyl-5-methyl-1,3-dioxolene-2-one

sodium 7-[(Z)-2-methoxyimino-2-(thiazol-4-yl)acetamido]-3-(3-methyl-1,2,4-thiadiazol-5-yl)thiomethyl-3-cephem-4-carboxylate

ethyl acetate

water

→

title compound

Ausbeute 62.3%

(5-Methyl-2-oxo-1,3-dioxolen-4-yl)methyl 7-[(Z)-2-methoxyimino-2-(thiazol-4-yl)acetamido]-3-(3-methyl-1,2,4-thiadiazol-5-yl)thiomethyl-3-cephem-4-carboxylate

Ausbeute 62.3%

Lösungsmittel

dimethylformamide

Reaktionsbedingungen

Aufarbeitung

1. 1
   workup.STIRRINGwith stirring
2. 2
   SonstigeThe ethyl acetate layer was separated
3. 3
   Waschenwashed successively with water (30 ml, adjusted to pH 3 with dil. HCl), 10% aqueous K2HPO4 solution (30 ml) twice
4. 4
   Trocknensaturated saline water, dried over MgSO4
5. 5
   Einengenconcentrated in vacuo
6. 6
   workup.ADDITIONthe residue was added dropwise to a mixture of diethyl ether (40 ml) and petroleum ether (40 ml)
7. 7
   FiltrationThe formed crystals were filtered
8. 8
   Waschenwashed with petroleum ether
9. 9
   Sonstigedried in vacuo

Vorschrift

4-Bromomethyl-5-methyl-1,3-dioxolene-2-one (386 mg) was added to a solution of sodium 7-[(Z)-2-methoxyimino-2-(thiazol-4-yl)acetamido]-3-(3-methyl-1,2,4-thiadiazol-5-yl)thiomethyl-3-cephem-4-carboxylate (536 mg) in dimethylformamide (5 ml) at -5° C. The mixture was stirred at this temperature for 1.3 hr and then poured into a mixture of ethyl acetate (130 ml) and water (30 ml, adjusted to pH 3 with dil HCl) with stirring. The ethyl acetate layer was separated, washed successively with water (30 ml, adjusted to pH 3 with dil. HCl), 10% aqueous K2HPO4 solution (30 ml) twice, and saturated saline water, dried over MgSO4, concentrated in vacuo, and the residue was added dropwise to a mixture of diethyl ether (40 ml) and petroleum ether (40 ml). The formed crystals were filtered, washed with petroleum ether, and dried in vacuo to give the title compound (390 mg). ##STR38##

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