Trans-2,2-dimethyl-3-(2,2-dichloroethenyl)cyclopropanecarbonyl chloride, which is animportant intermediate for insecticides, is obtained by isomerization of the cis/trans-mixture with4- (N,N-dimethylamino) pyridine (D...Trans-2,2-dimethyl-3-(2,2-dichloroethenyl)cyclopropanecarbonyl chloride, which is animportant intermediate for insecticides, is obtained by isomerization of the cis/trans-mixture with4- (N,N-dimethylamino) pyridine (DMAP) in the presence or absence of halogen compounds ingood yield.展开更多
糠醛、乙酸酐为原料,用4-二甲氨基吡啶(DMAP)作催化剂,在吡啶存在下,经Perk in反应一步合成了α-呋喃丙烯酸。考察了原料配比、反应温度和时间以及吡啶和DMAP用量对产物收率的影响,优化的工艺条件为:n(糠醛)∶n(乙酸酐)∶n(DMAP)∶n(吡...糠醛、乙酸酐为原料,用4-二甲氨基吡啶(DMAP)作催化剂,在吡啶存在下,经Perk in反应一步合成了α-呋喃丙烯酸。考察了原料配比、反应温度和时间以及吡啶和DMAP用量对产物收率的影响,优化的工艺条件为:n(糠醛)∶n(乙酸酐)∶n(DMAP)∶n(吡啶)=1∶3∶0.05∶1,反应温度140℃,反应时间30 m in,产物最终收率可达89.2%。展开更多
1,2-二棕榈酰-sn-甘油-3-磷脂酰胆碱(DPPC,1)不仅可作为药用辅料,还可作为外源性肺表面活性剂,治疗新生儿呼吸窘迫综合征(NRDS)。甘油磷脂酰胆碱(GPC,2)在DCM中,在4-二甲氨基吡啶(DMAP)和二环己基碳二亚胺(DCC)的作用下,与棕榈酸(PA,3)...1,2-二棕榈酰-sn-甘油-3-磷脂酰胆碱(DPPC,1)不仅可作为药用辅料,还可作为外源性肺表面活性剂,治疗新生儿呼吸窘迫综合征(NRDS)。甘油磷脂酰胆碱(GPC,2)在DCM中,在4-二甲氨基吡啶(DMAP)和二环己基碳二亚胺(DCC)的作用下,与棕榈酸(PA,3)反应得DPPC。但发现产生了某一杂质,严重影响产物的纯化。分离、纯化后经MS和1 H NMR确证,该杂质为1,1'-亚甲基双(4-二甲氨基吡啶鎓)双氯化物。把反应溶剂改为乙腈,并将DMAP投料时物质的量比例从3降低至1,目标产物1的收率由33.20%提升至49.18%,纯度99.92%。展开更多
This article presents a novel catalytic method by combining phase-transfer catalyst, benzyltriethylammonium chloride, with 4-dimethylaminopyridine for the syntheses of glycosyl esters from substituted phenoxyaeetie ac...This article presents a novel catalytic method by combining phase-transfer catalyst, benzyltriethylammonium chloride, with 4-dimethylaminopyridine for the syntheses of glycosyl esters from substituted phenoxyaeetie acids and the peracetate of α-D-l-bromosugars to produee eight novel β-glyeosyl esters in high yields. The struetures of the syn-thesized eompounds were established by IR, MS, ^1H NMR, and ^13C NMR speetra and elemental analyses.展开更多
文摘Trans-2,2-dimethyl-3-(2,2-dichloroethenyl)cyclopropanecarbonyl chloride, which is animportant intermediate for insecticides, is obtained by isomerization of the cis/trans-mixture with4- (N,N-dimethylamino) pyridine (DMAP) in the presence or absence of halogen compounds ingood yield.
文摘糠醛、乙酸酐为原料,用4-二甲氨基吡啶(DMAP)作催化剂,在吡啶存在下,经Perk in反应一步合成了α-呋喃丙烯酸。考察了原料配比、反应温度和时间以及吡啶和DMAP用量对产物收率的影响,优化的工艺条件为:n(糠醛)∶n(乙酸酐)∶n(DMAP)∶n(吡啶)=1∶3∶0.05∶1,反应温度140℃,反应时间30 m in,产物最终收率可达89.2%。
文摘1,2-二棕榈酰-sn-甘油-3-磷脂酰胆碱(DPPC,1)不仅可作为药用辅料,还可作为外源性肺表面活性剂,治疗新生儿呼吸窘迫综合征(NRDS)。甘油磷脂酰胆碱(GPC,2)在DCM中,在4-二甲氨基吡啶(DMAP)和二环己基碳二亚胺(DCC)的作用下,与棕榈酸(PA,3)反应得DPPC。但发现产生了某一杂质,严重影响产物的纯化。分离、纯化后经MS和1 H NMR确证,该杂质为1,1'-亚甲基双(4-二甲氨基吡啶鎓)双氯化物。把反应溶剂改为乙腈,并将DMAP投料时物质的量比例从3降低至1,目标产物1的收率由33.20%提升至49.18%,纯度99.92%。
基金Supported by the National Natural Science Foundation of China(No.20674023).
文摘This article presents a novel catalytic method by combining phase-transfer catalyst, benzyltriethylammonium chloride, with 4-dimethylaminopyridine for the syntheses of glycosyl esters from substituted phenoxyaeetie acids and the peracetate of α-D-l-bromosugars to produee eight novel β-glyeosyl esters in high yields. The struetures of the syn-thesized eompounds were established by IR, MS, ^1H NMR, and ^13C NMR speetra and elemental analyses.