A mathematical model for dilution crystallization of spectinomycin dihydrochloride pentahydrate was established on the basis of the population and mass balance. Three operating modes, i.e., constant mass rate addition...A mathematical model for dilution crystallization of spectinomycin dihydrochloride pentahydrate was established on the basis of the population and mass balance. Three operating modes, i.e., constant mass rate addition of diluent, constant mass fraction of diluent and constant size-independent growth rate, were investigated over a wide range of controlled parameters. The intrinsic characteristics of the crystallization process and the influence of operation parameters were analyzed in detail. Suitable strategy for better performance was suggested.展开更多
Diisopropylidenated α-D-glucofuranose （1） was oxidated with CrO3-pyridine complex. Oxidated product and its hydrate were separated and were reduced together to synthesize diisopropylidenated α-D-allofuranose （ 3...Diisopropylidenated α-D-glucofuranose （1） was oxidated with CrO3-pyridine complex. Oxidated product and its hydrate were separated and were reduced together to synthesize diisopropylidenated α-D-allofuranose （ 3）. The yield of 3 increased by 8% than that with only oxidated product as reduction substrate. Benzoylated derivative of 3 was selectively nydrolyzed and dimesylated to synthesize 3-O-benzoyl-1 .2- O- isopropylidene-α-D-allofuranose （ 5 ） and its dimesylated derivative respectively. The overall yield of 5 from 1 was 36%. Each step and final products were analyzed by ^1H-NMR spectra and other methods. The experiments showed that the influence of acetic acid concentration on selective hydrolysis was obvious. The hydrolysis yield was 81.8%. Oxidation. reduction and other procedures were practical and had application potential.展开更多
文摘A mathematical model for dilution crystallization of spectinomycin dihydrochloride pentahydrate was established on the basis of the population and mass balance. Three operating modes, i.e., constant mass rate addition of diluent, constant mass fraction of diluent and constant size-independent growth rate, were investigated over a wide range of controlled parameters. The intrinsic characteristics of the crystallization process and the influence of operation parameters were analyzed in detail. Suitable strategy for better performance was suggested.
基金Supported by Tianjin Natural Science Foundation ( No. 05YFJMJC09600).
文摘Diisopropylidenated α-D-glucofuranose （1） was oxidated with CrO3-pyridine complex. Oxidated product and its hydrate were separated and were reduced together to synthesize diisopropylidenated α-D-allofuranose （ 3）. The yield of 3 increased by 8% than that with only oxidated product as reduction substrate. Benzoylated derivative of 3 was selectively nydrolyzed and dimesylated to synthesize 3-O-benzoyl-1 .2- O- isopropylidene-α-D-allofuranose （ 5 ） and its dimesylated derivative respectively. The overall yield of 5 from 1 was 36%. Each step and final products were analyzed by ^1H-NMR spectra and other methods. The experiments showed that the influence of acetic acid concentration on selective hydrolysis was obvious. The hydrolysis yield was 81.8%. Oxidation. reduction and other procedures were practical and had application potential.
