A clean, simple, efficient synthesis of 1,8-dioxo-octahydroxanthenes derivatives using ionic liquid 1-butyl, 3-me- thylimidazolium perchlorate ([bmim] ClO4) has been developed. The method provides several advantages s...A clean, simple, efficient synthesis of 1,8-dioxo-octahydroxanthenes derivatives using ionic liquid 1-butyl, 3-me- thylimidazolium perchlorate ([bmim] ClO4) has been developed. The method provides several advantages such as simple work up, environmental friendliness and excellent yields in short reaction time. The ionic liquid [bmim] ClO4 used was recovered and reused for three times.展开更多
A facile and highly efficient protocol for the synthesis of 1,8-dioxo-octahydroxanthene derivatives was achieved through cascade Knoevenagel-Michael condensations and cyclo-dehydration reaction utilizing tetrachlorosi...A facile and highly efficient protocol for the synthesis of 1,8-dioxo-octahydroxanthene derivatives was achieved through cascade Knoevenagel-Michael condensations and cyclo-dehydration reaction utilizing tetrachlorosilane（TCS） as catalyst under mild conditions.Reaction of the titled compounds with TCSNaN_3 to give novel functionalized pyrano[3,2-c]tetrazolo[1,5-a]azepine derivatives is also described.展开更多
Ceric ammonium nitrate （CAN） supported HY-zeolite has been used as an efficient catalyst for the one- pot synthesis of 1,8-dioxo-octahydroxanthenes from the readily available 1,3-diketone and aromatic aldehydes unde...Ceric ammonium nitrate （CAN） supported HY-zeolite has been used as an efficient catalyst for the one- pot synthesis of 1,8-dioxo-octahydroxanthenes from the readily available 1,3-diketone and aromatic aldehydes under solvent-free conditions. The present methodology is cost-effective in addition to other advantages like high yields of products in shorter reaction time and simple workup procedure without the use of any injurious solvents.展开更多
在密封反应釜中,以1,8-对孟烷二乙酰胺为原料,正丁醇为溶剂,经氢氧化钠催化水解制备得到1,8-对孟烷二胺。当原料为0.1 mol,正丁醇用量为150 m L,原料与氢氧化钠物质的量之比为1∶5,反应温度175℃,体系自发升压至0.35～0.4 MPa,反应时间1...在密封反应釜中,以1,8-对孟烷二乙酰胺为原料,正丁醇为溶剂,经氢氧化钠催化水解制备得到1,8-对孟烷二胺。当原料为0.1 mol,正丁醇用量为150 m L,原料与氢氧化钠物质的量之比为1∶5,反应温度175℃,体系自发升压至0.35～0.4 MPa,反应时间18 h时,原料转化率为100%,产物选择性大于96%,产物GC含量可达96.47%。与常压工艺相比,密封工艺的反应时间缩短了50%,产物选择性提高了20个百分点;并且当投料量扩大到10倍时,仍保持良好的反应效果,还可适当减少溶剂的添加比例。采用减压蒸馏对密封工艺产品进行分离提纯,减压精馏对常压工艺产品进行分离提纯,结果发现:蒸馏方法使产品提纯用时减少了7/8,溶剂回收率提高了5.3个百分点,且可多次重复利用,产品得率提高了55.7个百分点,产品得率可达85.6%,纯度为96.51%。展开更多
文摘A clean, simple, efficient synthesis of 1,8-dioxo-octahydroxanthenes derivatives using ionic liquid 1-butyl, 3-me- thylimidazolium perchlorate ([bmim] ClO4) has been developed. The method provides several advantages such as simple work up, environmental friendliness and excellent yields in short reaction time. The ionic liquid [bmim] ClO4 used was recovered and reused for three times.
文摘A facile and highly efficient protocol for the synthesis of 1,8-dioxo-octahydroxanthene derivatives was achieved through cascade Knoevenagel-Michael condensations and cyclo-dehydration reaction utilizing tetrachlorosilane（TCS） as catalyst under mild conditions.Reaction of the titled compounds with TCSNaN_3 to give novel functionalized pyrano[3,2-c]tetrazolo[1,5-a]azepine derivatives is also described.
基金financial support received from Council of Scientific and Industrial Research(No.02(0025)/ 11/EMR-Ⅱ),New Delhi
文摘Ceric ammonium nitrate （CAN） supported HY-zeolite has been used as an efficient catalyst for the one- pot synthesis of 1,8-dioxo-octahydroxanthenes from the readily available 1,3-diketone and aromatic aldehydes under solvent-free conditions. The present methodology is cost-effective in addition to other advantages like high yields of products in shorter reaction time and simple workup procedure without the use of any injurious solvents.
