Preparation method of L--dihydrophenyl glycine sodium salt
A technology of dihydrophenylglycine methyl dungun sodium salt and dihydrophenylglycine is applied in the field of preparation of cephalosporin antibiotic raw materials, and can solve the problems of improving product yield and purity, affecting product yield, affecting cefradine production, and the like, and achieving The effect of reducing production costs
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Embodiment 1
[0025] Add 600kg of methanol solution containing 5% sodium methylate and 123kg of dihydrophenylglycine in the 1000L reactor, stir, control the reaction temperature in the range of 10-20 degrees, then slowly add 80kg of sodium methylate to the reactor, so that the reaction solution has When there is a small amount of undissolved dihydrophenylglycine, that is, when the reaction solution is slightly turbid, stop the dropwise addition, keep warm for 20 minutes, and filter to obtain a clear filtrate.
[0026] Heat the above filtrate with a water bath until there is a reflux liquid, start to add 102 kg of methyl acetoacetate dropwise, stir, and control the dropwise addition time at about 30 minutes. After the reaction liquid is completely clarified, continue the reflux reaction for 30 minutes. Change to a distillation pipeline, first distill at normal pressure, the temperature in the methanol tank is generally controlled below 60°C, when the distillate reaches about 300kg, slowly add...
Embodiment 2
[0028] Add 100kg of methanol solution containing 30% sodium methylate and 123kg of dihydrophenylglycine in the 1000L reactor, stir, control the reaction temperature in the range of 10-20 degrees, then slowly add 50kg of sodium methylate in the reactor, so that the reaction solution has When there is a small amount of undissolved dihydrophenylglycine, that is, when the reaction solution is slightly turbid, stop the dropwise addition, keep warm for 20 minutes, and filter to obtain a clear filtrate.
[0029] Heat the above filtrate with a water bath until there is a reflux liquid, start to add 102 kg of methyl acetoacetate dropwise, stir, and control the dropwise addition time at about 30 minutes. After the reaction liquid is completely clarified, continue the reflux reaction for 30 minutes. Change to a distillation pipeline, first distill at normal pressure, the temperature in the methanol tank is generally controlled below 60°C, when the distillate reaches about 300kg, slowly ad...
Embodiment 3
[0031] Add 600kg of methanol solution containing 8% sodium methylate and 123kg of dihydrophenylglycine in the 1000L reactor, stir, control the reaction temperature in the range of 10-20 degrees, then slowly add 100kg of sodium methylate in the reactor, so that the reaction solution has When there is a small amount of undissolved dihydrophenylglycine, that is, when the reaction solution is slightly turbid, stop the dropwise addition, keep warm for 20 minutes, and filter to obtain a clear filtrate.
[0032] Heat the above filtrate with a water bath until there is a reflux liquid, start to add 102 kg of methyl acetoacetate dropwise, stir, and control the dropwise addition time at about 30 minutes. After the reaction liquid is completely clarified, continue the reflux reaction for 30 minutes. Change to a distillation pipeline, first distill at normal pressure, the temperature in the methanol tank is generally controlled below 60°C, when the distillate reaches about 300kg, slowly ad...
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