Réaction #62778

Équation de réaction

diisopropyl ether

anisole

trifluoroacetic acid

benzhydryl 7-[2-(2-tritylaminothiazol-4-yl)-2-difluoromethoxyiminoacetamido]-3-(1-methyl-1-pyrrolidiniomethyl)-3-cephem-4-carboxylate trifluoroacetate

→

7-[2-(2-aminothiazol-4-yl)-2-difluoromethoxyiminoacetamido]-3-(1-methyl-1-pyrrolidiniomethyl)-3-cephem-4-carboxylate

Rendement 72.4%

Solvants

methylene chloride

Conditions de réaction

Traitement

1. 1
   Autrethe resultant precipitates
2. 2
   Filtrationwere collected by filtration
3. 3
   Lavagewashed with diisopropyl ether
4. 4
   workup.DISSOLUTIONdissolved in water (400 ml)
5. 5
   Lavagethe elution
6. 6
   workup.ADDITIONThe fractions containing the object compound
7. 7
   Autrewere collected
8. 8
   Concentrationconcentrated in vacuo

Mode opératoire

A solution of benzhydryl 7-[2-(2-tritylaminothiazol-4-yl)-2-difluoromethoxyiminoacetamido]-3-(1-methyl-1-pyrrolidiniomethyl)-3-cephem-4-carboxylate trifluoroacetate (syn isomer) (1.25 g) in methylene chloride (4 ml) was stirred at 0°-5° C., and anisole (2.6 ml) and trifluoroacetic acid (5.2 ml) were added thereto. The mixture was stirred for one hour at 0°-5° C. To the reaction mixture was added diisopropyl ether, and the resultant precipitates were collected by filtration, washed with diisopropyl ether and dissolved in water (400 ml). The solution was subjected to column chromatography on macroporus non-ionic adsorption resin "Diaion HP-20" and the elution was carried out with 30% aqueous solution of methanol. The fractions containing the object compound were collected, concentrated in vacuo and lyophilized to give 7-[2-(2-aminothiazol-4-yl)-2-difluoromethoxyiminoacetamido]-3-(1-methyl-1-pyrrolidiniomethyl)-3-cephem-4-carboxylate (syn isomer) (450 mg).

Source