反应详情

Anhydrous pyridine (31 ml, 0.384 mole) was added to a solution of phosphorus pentachloride (20 g, 96 mmole) in dry dichloromethane (300 ml) at 3°. The suspension was stirred for 10 minutes at 3° and diphenylmethyl (6R,7R)-7-(thien-2-ylacetamido)-3-trichloroacetylcarbamoyloxymethylceph-3-em-4-carboxylate (22.5 g, 32 mmole) was added; the reaction was stirred at ca. 2° for 1 hour. The dark solution was poured slowly into a cold (0°) anhydrous mixture of methanol (80 ml) and dichloromethane (200 ml) with the temperature kept below 5°. The temperature of the solution was then allowed to rise to 23° and, after stirring the solution at this temperature for 1 hour, water (200 ml) was added. The organic layer was separated and washed with 2N-sulphuric acid, water, sodium bicarbonate solution and water, dried over magnesium sulphate, and evaporated in vacuo. The resulting oil was dissolved in ethyl acetate and a solution of toluene-p-sulphonic acid monohydrate (6.0 g, 31.5 mmole) in ethyl acetate was added. The combined solutions (ca. 350 ml) were poured into diethyl ether (ca. 1 liter) and the resulting solid was filtered off and dried in vacuo to give the title compound (17.2 g, 72%), m.p. 150° to 153°; [α]D21° + 7.5° (c 0.82 in DMSO); λmaxEtOH 263 nm (ε 7,600) and λinf.EtOH 267 nm (ε 7,350). IR, NMR and microanalytical data confirmed the structure as that of the title compound.

1. stirringthe reaction was stirred at ca. 2° for 1 hour
2. customkept below 5°
3. customto rise to 23°
4. stirringafter stirring the solution at this temperature for 1 hour
5. customThe organic layer was separated
6. washwashed with 2N-sulphuric acid, water, sodium bicarbonate solution and water
7. dry with materialdried over magnesium sulphate
8. customevaporated in vacuo
9. dissolutionThe resulting oil was dissolved in ethyl acetate
10. filtrationthe resulting solid was filtered off
11. customdried in vacuo