The preparation method of cefmetazole
A technology of cefmetazole acid and cephem, which is applied in the field of preparation of cephalosporins, can solve the problems of high raw material cost, difficult production control, low product yield and product purity, etc., so as to reduce production cost and increase the yield of finished products , good protection effect
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Embodiment 1
[0037] At room temperature, in a clean three-necked flask, add 60.0g of 3-TZ in 200ml of dimethyl carbonate solvent. After stirring, add 21.6g of trimethylchlorosilane to protect the carboxyl group by silanization. The temperature is raised to 25°C and reacted for 1h. Cool down to 0°C, add 120g of N,N dimethylacetamide, control the temperature of the dropping process to 0~5°C, after the dropwise addition, heat up to 30°C, add 6.4g methanol, and then add 43.6g di-tert-dicarbonate in batches Butyl ester (BOC acid anhydride), after the addition, keep for 2h to fully react.
[0038] After the reaction is completed, concentrate under reduced pressure to remove the dimethyl carbonate solvent, add 1000ml of chloroform solvent, stir evenly, reduce to -30°C, add 80g of 30% sodium methoxide solution, and control the temperature during the dropping process below -30°C. After the addition, the temperature was raised to -20°C and reacted for 30 minutes to obtain the methoxidation reaction sol...
Embodiment 2
[0042] At room temperature, in a clean three-necked flask, add 60.0g (0.18mol) 3-TZ in 280ml acetonitrile solvent. After stirring evenly, add 27.6g (0.18mol) trimethylbromosilane to protect the carboxyl group by silanization and increase the temperature to 25℃ , React for 1h, then lower the temperature to 0°C, add 90g of N,N dimethylformamide, control the temperature during the dropping process to 0~5°C, after the dropwise addition, heat up to 30°C, add 7.7g (0.29mol) methanol, then Add 62.8g (0.29mol) of di-tert-butyl dicarbonate (BOC anhydride) in batches. After the addition, keep for 2h to fully react.
[0043] After the reaction is complete, concentrate under reduced pressure to remove the dimethyl carbonate solvent, add 1200ml of dichloromethane solvent, stir evenly, reduce to -30°C, add 30% sodium methoxide solution 97.2g (0.54mol), add dropwise to the process temperature The temperature is controlled below -30°C, after the addition, the temperature is raised to -20°C, and ...
Embodiment 3
[0047] At room temperature, in a clean three-necked flask, add 60.0g (0.18mol) 3-TZ in 350ml of toluene solvent. After stirring evenly, add 54.0g (0.27mol) of trimethylsilyl iodide to protect the carboxyl group by silanization and increase the temperature to 25℃ , React for 1h, then lower the temperature to 0℃, add 150g of triethylamine, control the temperature of the dripping process from 0 to 5℃, after the dripping, heat up to 30℃, add 11.5g (0.36mol) methanol, and then add 78.5g in batches (0.36mol) di-tert-butyl dicarbonate (BOC acid anhydride), after the addition, keep for 2h, and fully react.
[0048] After the reaction is over, concentrate under reduced pressure to remove the dimethyl carbonate solvent, add 1500ml of chloroform solvent, stir evenly, reduce to -30℃, add 30% lithium methoxide solution 45.6gg (0.36mol), and control the temperature during the dropping process After the addition is below -30°C, the temperature is raised to -20°C and reacted for 30 minutes to ob...
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