Medium pressure liquid chromatography

Hish-Pressure/Medium-Pressure Liquid Chromatography (HPLC/MPLC)... 

The reaction mixture is cooled, diluted with 100 mL of sat. aq NaCI and extracted with four 50-mL portions of Ei,0. The combined ethereal extracts are washed with 50 ml. of sat. aq NaCI, dried, filtered and concentrated to a volume of a few milliliters. 20 ntL of petroleum ether arc added to precipitate the soluble salts. The mixture is filtered through a silica gel column (petroleum ether)and purified by medium-pressure liquid chromatography yield 360 mg (65%). 

The diastereomeric /1-hydroxysulfoximines derived from prostereogenic ketones are generally separable by medium-pressure liquid chromatography (WLC) on silica gel. Subsequent desulfurization of the separated adducts affords both enantiomers of the tertiary alcohols with high optical purity58,59. 

The synthesis of 6-hydroxy fluvastatin with M. rammaniana DSM 62752 gave high conversion (>95 %) in shake flask culture on 400 mL scale with 0.1 g L of fluvastatin as well as on 22 L scale in a Wave bioreactor-fed batch process at a final substrate concentration of 0.4 g L Instead of the partial purification by a second solid-phase extraction described above, 6-hydroxy fluvastatin can be obtained in high purity ( 95 %) by, for example, preparative medium-pressure liquid chromatography (MPLC) on RP18 silica gel. ... 

The term medium-pressure liquid chromatography (MPLC) covers a wide range of column diameters, different granulometry packing materials, different pressures, and a number of... 

Leutert, T. and von Arx, E., Praparative Mitteldruck-fliissigkeitschromatographie (Preparative medium-pressure liquid chromatography), J. Chromatogr., 292, 333, 1984. 

Zogg, G.C., N dredy, Sz., and Sticher, O., Operating conditions in preparative medium pressure liquid chromatography (MPLC). II. Influence of solvent strength and flow rate of the mobile phase, capacity and dimensions of the column, J. Liq. Chromatogr., 12, 2049, 1989. 

From other approaches to optically active [2.2]metacyclophanes the following are noteworthy as just mentioned for 64 (medium pressure) liquid chromatography on microcrystalline triacetylcellulose (cf. Ref. 82 ) in ethanol or ether (practicable also at lower temperatures) is a very efficient and successful method for the optical resolution of many axial and planar chiral (aromatic) compounds 83). In many cases baseline-separations can be achieved and thereby both enantiomers obtained with known enantiomeric purity and in amounts sufficient for further investigations, especially for studying their chiroptical properties (see also 3.2 and 3.3). The disub-stituted [2.2]metacyclophanes 57 and 59 (which had been previously correlated to many other derivatives) 78- 79) were first resolved by this method83). 

Medium pressure liquid chromatography (MPLC) Lobar Li Chroprep Si 60 (40-63 pm) column (E.M. Merck)... 

The submitters purified the product by medium pressure liquid chromatography on a 60-cm x 5-cm column packed with 230-400 mesh silica gel 60 purchased from E. Merck. Ethyl acetate was used as eluant at a flow rate of 4 0 mL per min. Fractions (20 mL) were collected and analyzed by thin layer cHromatography. 

The medium-pressure liquid chromatography system (MPLC) was purchased from Baeckstrbm SEPARO AB. 

Platinum porphyrin complexes can be prepared by reaction with PtCl2(PhCN)2. Purification of the final complex is by medium pressure liquid chromatography on alumina. The strongly phosphorescent platinum(II) porphyrin complexes are efficient sensitizers for stilbene isomerization. The quantum yields for the cis to trans process are greater than unity because of a quantum chain process in which the metalloporphyrin serves both as an energy donor and an acceptor.1110 Picosecond laser spectroscopy has been used to obtain time-resolved excited-state spectra of platinum octaethylporphyrin complexes, and to probe the excited-state energy levels.1111 Tetrabenzoporphyrin complexes have been prepared for platinum in both the divalent and tetravalent oxidation states. The divalent complex shows strong phosphorescence at 745 nm.1112... 

The use of medium pressure liquid chromatography is described by Mqyers.3... 

Deacetamidocolchicine (18) was prepared by the classic syntheses of Eschenmoser (38) and van Tamelen (39). The racemate was resolved by medium-pressure liquid chromatography on swollen, microcrystalline cellulose triacetate prepared at 5°C, and the enantiomers were collected at -70°C (32). The (-)-enantiomer with the same biaryl configuration as natural (aS,7S)-colchicine (1) was eluted first and found to be essentially optically pure. Thermal racemization of the optical isomers gave the ther-... 

It was found that root bark, containing egg cavities with feces, were avoided by the pine weevil H. abietis, so its feces were investigated in an attempt to find ways to control the weevil. After fractionation by medium-pressure liquid chromatography (MPLC) and analysis with gas chromatography-mass spectroscopy (GC-MS)... 

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