公开(公告)号：US3375082A

公开(公告)日：1968-03-26

申请号：US45155965

申请日：1965-04-28

Applicant: HOECHST AG

Inventor： GRAF RODERICH

IPC: B01D9/00 ,  B01D9/02 ,  C07C51/43 ,  C07D201/16 ,  C07D205/08 ,  C30B13/32

CPC classification number: C07D205/08 ,  B01D9/0013 ,  B01D9/004 ,  B01D9/0063 ,  C07C51/43 ,  C07C317/00 ,  C07D201/16 ,  C07C57/08

Abstract: 1,100,426. Crystal - melt reflux. FARBWERKE HOECHST A.G. 29 April, 1965 [29 April, 1964], No. 18090/65. Heading B1G. [Also in Division F4] A high-melting component is separated in pure form from a mixture by passing the mixture into an intermediate zone of a vertical fractionation column which is cooled at the top and heated at the bottom. Crystals of the high - melting component fall downwards through the column and are melted at the bottom, a portion of the melt rises so effecting reflux, and the remainder of the melt is withdrawn as product. Component-depleted solvent is withdrawn from the top of the column. The amount of solvent employed may be 10 times that of the impurity to be removed. Substances purified may be 4,4-dimethyl-acetidnone-2 (from diisopropyl ether), dimethyl sulphoxide (from isopropyl chloride), and crotonic acid (from diisopropyl ether). According to the Figure, solution passes from a pipe 4 into a column 1 between cooling jackets 2 and 3, solvent passes out through a pipe 8, crystals are melted by heating jacket 13, and melt passes out through a pipe 6. The solution is stirred by a perforated blade 9 which may rotate in alternate directions. The temperature in the column is measured at points T 1-3 .