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At 21 ° C,35g cefotaxime side chain acid and 48gDMWas added to a mixture of dichloro and acetonitrile (the mass of the mixture was 250 g and the density was 1.0 g / cm 3)After stirring for 10 min,1.0 mL of pyridine was added,At 22 ° C, triethylamine (8.0 mL)After the addition was completed, the temperature was raised to 30 ° C., the reaction was incubated for 50 minutes, cooled,28 ml of triethyl phosphite was added dropwise at 21 ° C,Drop when the process of sharing 2.5h,After the addition was completed, the reaction was incubated at 21 ± 1 ° C for 3.0 h,Then cooled to 3 incubated reaction 30min, suction filtration,And dried at 60 to ceftazidime side chain acid active ester, the yield was 92.6percentThe content is 99.3percent.
General procedure: At 78 C, 1.6M n-butyllithium in hexane (1.25 mL) was addeddropwise to a solution of 1,10-<strong>[1293-65-8]dibromoferrocene</strong> (0.69 g, 2.0 mmol)in 10 mL THF. The reaction mixture was stirred at the same temperaturefor 0.5 h before adding 2,2,6,6-tetramethylpiperidine(0.40 mL, 2.2 mmol) dropwise. The reaction mixture was stirredfor 3 h, keeping the temperature below 40 C. A solution of tetramethylthiuramdisulfide (0.48 g, 2.0 mmol) in 20 mL THF wasadded, and the reaction mixture was slowly warmed to roomtemperature. After adding water (5 mL), the reaction mixture wasextracted with dichloromethane (2 x 40 mL). The collected organiclayers were washed with water (2 x 20 mL) and dried with anhydroussodium sulfate. After removing the solvent under reducedpressure, the crude product was purified by column chromatography(alumina, dichloromethane/hexane 3:7) to afford P1 as ayellow solid (0.33 g, 43%).