反应详情

Methanesulfonyl chloride (0.61 ml) was added to a solution of 2-(2-aminothiazol-4-yl)-2-(3-thietanyloxyimino)acetic acid (syn isomer, 0.99 g) and N,N-diisopropyl-N-ethylamine (1.33 ml) in N,N-dimethylformamide (20 ml) at -55° to -50° C., and the mixture was stirred for 10 minutes to produce an activated acid solution. To a solution of bis(trifluoroacetic acid) salts of 7β-amino-3-(2-methyl- 1-pyrazolio)methyl-3-cephem-4-carboxylate (2 g) and N,O-bis(trimethylsilyl)acetamide (3.79 ml) in tetrahydrofuran (20 ml) was added the above activated acid solution under ice-cooling, and the reaction mixture was stirred at the same temperature for an hour. The resultant mixture was poured into diethyl ether, and the precipitates were collected by filtration. The precipitates were suspended in water (20 ml), and the suspension was adjusted to pH 5 with 5% aqueous solution of sodium bicarbonate and subjected to column chromatography on macroporous non-ionic adsorption resin "Diaion HP-20" (Trademark, manufactured by Mitsubishi Chemical Industries) and eluted with 10% aqueous solution of isopropyl alcohol. The fractions containing the object compound were collected, evaporated in vacuo to remove isopropyl alcohol, and lyophilized to give 7β-[2-(2-aminothiazol-4-yl)-2-(3-thietanyloxyimino)acetamido]-3-(2-methyl-1-pyrazolio)methyl-3-cephem-4-carboxylate (syn isomer, 0.5 g).

1. customto produce an activated acid solution
2. temperaturecooling
3. stirringthe reaction mixture was stirred at the same temperature for an hour
4. filtrationthe precipitates were collected by filtration
5. wash" (Trademark, manufactured by Mitsubishi Chemical Industries) and eluted with 10% aqueous solution of isopropyl alcohol
6. additionThe fractions containing the object compound
7. customwere collected
8. customevaporated in vacuo
9. customto remove isopropyl alcohol