A concise route for the total syntheses of benzopranylchalcones from 2,4,6-trihydroxyacetophone(3) and citral(8), by means of cyclization, methoxy-protection and aldol-condensation is described. Two benzopranylchalcon...A concise route for the total syntheses of benzopranylchalcones from 2,4,6-trihydroxyacetophone(3) and citral(8), by means of cyclization, methoxy-protection and aldol-condensation is described. Two benzopranylchalcones, Boesenbergin B(1) and Boesenbergin A(2) were synthesized from 2,4,6-(trihydroxyacetophone)(3), citral(8) and benzaldehyde(9) via the route. The total yields of compounds 1 and 2 were 26% and 11%, respectively. In the cyclization step, the yields of key intermediates 4 and 7 were 40% and 42%, respectively.展开更多
A series of 2 amino 3 cyano 4 aryl 4H benzochromenes were synehesized by the reaction of malononitrile and 1 naphthol with corresponding aromatic aldehydes in ethanol in the presence of piperidine as catalyst. The str...A series of 2 amino 3 cyano 4 aryl 4H benzochromenes were synehesized by the reaction of malononitrile and 1 naphthol with corresponding aromatic aldehydes in ethanol in the presence of piperidine as catalyst. The structures of all compounds obtained were characterized by elemental analysis, IR, 1H NMR and single crystal X ray diffractometry. X ray crystal structure analysis indicates compound 4b crystallizes in monoclinic, with space group C2/c, a = 2 422 1(6) nm , b = 0 901 6(2) nm , c = 1 700 3(5) nm , β =93 16(1)°, V = 3 707 4(15) nm 3 , Z =8, D c= 1 284 g/cm 3 , I≥2σ(I) =2 141, R = 0 043 2 , wR = 0 108 5 . Compared to other methods, this method has the advantages of simple operation and good yields.展开更多
A series of 2 amimo 3 cyano 7,7 dimethyl 4 aryl 5 oxo 5,6,7,8 tetra 4H chromenes were synthesized in the absence of catalyst. Their structures were determined by IR, 1H NMR, and single crystal X ray diffraction.
以80%水合肼为还原剂、FeCl_3/C为催化剂,还原6-硝基-1,2-苯并吡喃酮制备6-氨基-1,2-苯并吡喃酮,并通过~1 H NMR、IR、^(13)C NMR和LC-MS表征了目标产物的结构,HPLC分析纯度达99%以上。同时探究了水合肼用量、反应温度、反应时间以及催...以80%水合肼为还原剂、FeCl_3/C为催化剂,还原6-硝基-1,2-苯并吡喃酮制备6-氨基-1,2-苯并吡喃酮,并通过~1 H NMR、IR、^(13)C NMR和LC-MS表征了目标产物的结构,HPLC分析纯度达99%以上。同时探究了水合肼用量、反应温度、反应时间以及催化剂用量对反应的影响。较佳的合成工艺条件为:n(80%水合肼)∶n(6-硝基-1,2-苯并吡喃酮)=2.5,FeCl_3用量为0.8g,活性炭用量为0.2g,反应温度为78℃,反应时间3.5h,收率可达85.0%。展开更多
The novel type tetramethinmerocyanine red sensitive dyes with benzopyran nucleus on the bridged chain is synthesized by alkaline heterocyclic compound,3-carboxylmethyl rodanine,and chromone.The visible absorption spec...The novel type tetramethinmerocyanine red sensitive dyes with benzopyran nucleus on the bridged chain is synthesized by alkaline heterocyclic compound,3-carboxylmethyl rodanine,and chromone.The visible absorption spectra in methanol and the sensitizing spectra in AgBr-AgI emulsion are determined.Among those dyes,the sensitizing dye used for laser image film is selected.The result shows that the photographic sensitivity is high and photographic properties are stable,especially the residual color is very little after processing.展开更多
文摘A concise route for the total syntheses of benzopranylchalcones from 2,4,6-trihydroxyacetophone(3) and citral(8), by means of cyclization, methoxy-protection and aldol-condensation is described. Two benzopranylchalcones, Boesenbergin B(1) and Boesenbergin A(2) were synthesized from 2,4,6-(trihydroxyacetophone)(3), citral(8) and benzaldehyde(9) via the route. The total yields of compounds 1 and 2 were 26% and 11%, respectively. In the cyclization step, the yields of key intermediates 4 and 7 were 40% and 42%, respectively.
文摘A series of 2 amino 3 cyano 4 aryl 4H benzochromenes were synehesized by the reaction of malononitrile and 1 naphthol with corresponding aromatic aldehydes in ethanol in the presence of piperidine as catalyst. The structures of all compounds obtained were characterized by elemental analysis, IR, 1H NMR and single crystal X ray diffractometry. X ray crystal structure analysis indicates compound 4b crystallizes in monoclinic, with space group C2/c, a = 2 422 1(6) nm , b = 0 901 6(2) nm , c = 1 700 3(5) nm , β =93 16(1)°, V = 3 707 4(15) nm 3 , Z =8, D c= 1 284 g/cm 3 , I≥2σ(I) =2 141, R = 0 043 2 , wR = 0 108 5 . Compared to other methods, this method has the advantages of simple operation and good yields.
文摘A series of 2 amimo 3 cyano 7,7 dimethyl 4 aryl 5 oxo 5,6,7,8 tetra 4H chromenes were synthesized in the absence of catalyst. Their structures were determined by IR, 1H NMR, and single crystal X ray diffraction.
文摘以80%水合肼为还原剂、FeCl_3/C为催化剂,还原6-硝基-1,2-苯并吡喃酮制备6-氨基-1,2-苯并吡喃酮,并通过~1 H NMR、IR、^(13)C NMR和LC-MS表征了目标产物的结构,HPLC分析纯度达99%以上。同时探究了水合肼用量、反应温度、反应时间以及催化剂用量对反应的影响。较佳的合成工艺条件为:n(80%水合肼)∶n(6-硝基-1,2-苯并吡喃酮)=2.5,FeCl_3用量为0.8g,活性炭用量为0.2g,反应温度为78℃,反应时间3.5h,收率可达85.0%。
文摘The novel type tetramethinmerocyanine red sensitive dyes with benzopyran nucleus on the bridged chain is synthesized by alkaline heterocyclic compound,3-carboxylmethyl rodanine,and chromone.The visible absorption spectra in methanol and the sensitizing spectra in AgBr-AgI emulsion are determined.Among those dyes,the sensitizing dye used for laser image film is selected.The result shows that the photographic sensitivity is high and photographic properties are stable,especially the residual color is very little after processing.
