Dry Column Vacuum Chromatography

Abstract

D r y C o l u m n V a c u u m C h r o m a t o g r a p h y Abstract: Chromatographic purification is an integrated part of organic synthesis. The Dry Column Vacuum Chromatography presented here, has excellent resolving power, is easily applied to large scale chromatography (up to 100 g) and is fast. Furthermore, the technique is economical and environmentally friendly due to significant reductions in solvent and the amount of silica used. Therefore, it is an excellent alternative to the commonly used Flash Column Chromatography for purification in organic synthesis.

Bioactive Constituents of the Root Bark of Artocarpus rigidus subsp. rigidus

“…The two singlet signals at d 3.81 (H-9) and 2.30 (H-11) were attributable to the -CH 2 COCH 3 substituent at the 2-position. The presence of the saturated keto group at C-10 was confirmed by the 13 C-NMR resonance at d 201.0. HMBC experiments (see Fig.…”

“…The CHCl 3 extract (14.9 g) was fractionated by quick column chromatography 13) (Merck silica gel 60 PF 254 , 250 g), eluting with n-hexane-CHCl 3 , CHCl 3 , and CHCl 3 -MeOH with increasing amounts of the more polar solvent. The eluates were examined by TLC and 12 combined fractions (C1-C12) were obtained.…”

Time-Pulsed Vacuum and Time-Pulsed Alternating Pressure Chromatography

“…The second reversal returns the solute over the stationary phase that has adsorbed even more of the solute, thereby increasing further the value of the retention factor, k 3 .…”

“…One of the major innovations in this field was the development of flash column chromatography as reported in 1978 by Still 2 (as of November 2013, this paper has been cited more than 8048 times according to the ISI Web of Knowledge). Other forms of column chromatography such as dry column chromatography, 3 and vacuum chromatography 4 have also been developed for separation. In addition, methods that change some of the physical parameters of separation and solvent flow, such as spinning disk chromatography (Chromatotron), have been used.…”

Novel synthesis of quinazolino[3,2-a][1,5]benzodiazepines: an experimental and computational study

“…The reaction progress and the purity of the compounds were controlled by TLC on a Merck precoated silica gel aluminum roll (60F254) with chloroform-ethyl acetate-methanol (ν/ν, 14:7:1) as the eluent. Dry column vacuum chromatography 42 was performed with silica gel 60 (0.015-0.040 mm, Merck). Microanalyses were performed with Thermo Scientific TM Flash 2000 CHNS/O analyser.…”