Phosphodiesterase Ⅴ inhibitor Sildenafil was synthesized by a new synthetic route.The hydrazine hydrate was used as deoxidizer in synthesizing of intermediate 4 amino 1 methyl 3 n propylpyrazole 5 carboxamide,the yie...Phosphodiesterase Ⅴ inhibitor Sildenafil was synthesized by a new synthetic route.The hydrazine hydrate was used as deoxidizer in synthesizing of intermediate 4 amino 1 methyl 3 n propylpyrazole 5 carboxamide,the yield being 91 5%.Surfactants was used in the process of the cycliztion.The yield was 8% higher than the original technology.This route is unique in that only common reagents are required.rection conditions are mild,and the process is simple,being with out use of silicon colum chromatography treatment.It is therefore suitable for industrial production.展开更多
2,4Dimethyl2(4methyl3Pentenyl)1,3dioxolane were synthesized with the phosphotungstic acid supported on cationic exchange resin as a catalyst.Various factors that affect the condensation yield were inve...2,4Dimethyl2(4methyl3Pentenyl)1,3dioxolane were synthesized with the phosphotungstic acid supported on cationic exchange resin as a catalyst.Various factors that affect the condensation yield were investigated.The results showed that the optimum conditions were as follows:6methyl5heptene2one:1,2Propandiol:catalyst:dehydrating agent is 1 mol:15mol∶12g∶200ml;reaction temperature was reflux temperature;reaction time was 25h.The yield was above 915% under the optimum conditions.The catalyst can be used repeatedly.展开更多
It is found that in the medium of H2SO4,the fading reaction of Beryllium Ⅲ is accelerated by IO-3 with the KBr.The fading of the color intensity of Beryllium Ⅲ is found to be directly proportional to the amount of i...It is found that in the medium of H2SO4,the fading reaction of Beryllium Ⅲ is accelerated by IO-3 with the KBr.The fading of the color intensity of Beryllium Ⅲ is found to be directly proportional to the amount of iodinate present.Based on these facts,a photometric method for the determination of iodine in salt was proposed.The decrease in absorbency（ΔA） was measured at the wavelength of 485 nm which is the absorption maximum of Beryllium Ⅲ.The detection limit is 1.47×10-8g/mL and the linear range is 0～12 μg/10 ml for iodine.展开更多
文摘Phosphodiesterase Ⅴ inhibitor Sildenafil was synthesized by a new synthetic route.The hydrazine hydrate was used as deoxidizer in synthesizing of intermediate 4 amino 1 methyl 3 n propylpyrazole 5 carboxamide,the yield being 91 5%.Surfactants was used in the process of the cycliztion.The yield was 8% higher than the original technology.This route is unique in that only common reagents are required.rection conditions are mild,and the process is simple,being with out use of silicon colum chromatography treatment.It is therefore suitable for industrial production.
文摘2,4Dimethyl2(4methyl3Pentenyl)1,3dioxolane were synthesized with the phosphotungstic acid supported on cationic exchange resin as a catalyst.Various factors that affect the condensation yield were investigated.The results showed that the optimum conditions were as follows:6methyl5heptene2one:1,2Propandiol:catalyst:dehydrating agent is 1 mol:15mol∶12g∶200ml;reaction temperature was reflux temperature;reaction time was 25h.The yield was above 915% under the optimum conditions.The catalyst can be used repeatedly.
文摘It is found that in the medium of H2SO4,the fading reaction of Beryllium Ⅲ is accelerated by IO-3 with the KBr.The fading of the color intensity of Beryllium Ⅲ is found to be directly proportional to the amount of iodinate present.Based on these facts,a photometric method for the determination of iodine in salt was proposed.The decrease in absorbency（ΔA） was measured at the wavelength of 485 nm which is the absorption maximum of Beryllium Ⅲ.The detection limit is 1.47×10-8g/mL and the linear range is 0～12 μg/10 ml for iodine.
