Organic-phase separation

To a solution of m-ethyl cinnamate (44, 352 mg, 85% pure, 1.70 mmol) and 4-phenylpyridine-A-oxide (85.5 mg, 29 mol%) in 1,2-dichloromethane (4.0 mL) was added catalyst 12 (38.0 mg, 3.5 mol%). The resulting brown solution was cooled to 4°C and then combined with 4.0 mL (8.9 mmol) of pre-cooled bleach solution. The two-phase mixture was stirred for 12 h at 4°C. The reaction mixture was diluted with methyl-t-butyl ether (40 mL) and the organic phase separated, washed with water (2 x 40 mL), brine (40 mL), and then dried over Na2S04. The drying agent was removed by filtration the mother liquors concentrated under reduce pressure. The resulting residue was purified by flash chromatography (silica gel, pet ether/ether = 87 13 v/v) to afford a fraction enriched in cis-epoxide (45, cis/trans . 96 4, 215 mg) and a fraction enriched in trans-epoxide cis/trans 13 87, 54 mg). The combined yield of pure epoxides was 83%. ee of the cis-epoxide was determined to be 92% and the trans-epoxide to be 65%. 

FIG. 1 Schematic drawing of the high-speed stirring (HSS) apparatus. An organic phase separated from the dispersed system by the teflon phase separator is continuously circulated through the photodiode array detector. 

Aqueous NaOH (50%, 50 ml) is added to the cyclopentadienone (1.3 mmol), the haloalkane (0.9 mmol) and TEBA-CI (0.9 mmol) in PhH (50 ml) and the mixture is stirred at room temperature for ca. 12 h. H20 (100 ml) is then added and the organic phase separated. The aqueous phase is extracted with PhH (2 x 25 ml) and the dried (MgS04) extracts are evaporated to yield the cyclopropane derivatives. 

After 24 or 48 h, diethyl ether (if not present since the beginning) was added to extract the product. The two-phase system was placed in a 25 mL separatory funnel and the organic phase separated and dried with anhydrous sodium sulfate. 

SYNTHESIS A solution of 0.67 g 5-hydroxyindole (indol-5-ol) in 10 ml dry MeOH was treated with a solution of 0.30 g NaOMe in MeOH, followed by 0.70 g benzyl chloride. The mixture was heated on the steam bath for 0.5 h, and the solvent removed under vacuum. The residue was suspended between H20 and CH2CI2, the organic phase separated and the aqueous phase extracted once with CH2CI2. The combined organics were stripped of solvent under vacuum, and the residue distilled. A colorless fraction came over at 170-190 °C and spontaneously crystallized in the receiver. There was obtained 0.90 g (80%) 5-benzyloxyindole with a mp 81-86 °C which increased, on recrystallization from toluene / hexane, to 94-96 °C. A sample prepared from the decarboxylation of 5-benzyloxyindole-2-carboxylic acid has been reported to have a mp of 102 °C from benzene. 

Benzylideneaniline (18.1 g, 0.1 mol) and tetrabutylammonium hydrogen sulphate (0.5 g, 1.35 mol) are dissolved in dichloromethane (100 ml) and a layer of 50 per cent aqueous sodium hydroxide introduced under this solution. Trimethylsulphonium iodide (20.4 g, 0.1 mol) is then added and the whole warmed at 50 °C with vigorous stirring for 2 hours, whereupon the originally undissolved sulphonium salt disappears. The mixture is poured on to ice, the organic phase separated, washed with water and dried. The solvent is evaporated and the residue distilled under reduced pressure to afford 1,2-diphenylaziridine (94%), b.p. 120°C/0.05mmHg. 

Analytical Properties p-Cyclodextrin SN or RN (cycloheptamylose-SN, -RN) note that the modifying ligand has a stereogenic center useful for normal phase, reverse phase, and polar organic phase separation under specific circumstances the substrate performs best with normal phase and polar organic mobile phases the SN modification has shown the highest selectivity Reference 13-28... 

Analytical Properties Substrate has 38 chiral centers and 7 aromatic rings surrounding 4 cavities (A, B, C, D), making this the most structurally complex of the macrocyclic glycopeptides substrate has a relative molecular mass of 2066 this phase can be used in normal, reverse, and polar organic phase separations selective for anionic chiral species with polar organic mobile phases, it can be used for a-hydroxy acids, profens, and N-blocked amino acids in normal phase mode, it can be used for imides, hydantoins, and N-blocked amino acids in reverse phase, it can be used for a-hydroxy and halogenated acids, substituted aliphatic acids, profens, N-blocked amino acids, hydantoins, and peptides Reference 47, 48... 

To a solution of 34.6 g of 2-(pyrrol-l-yl)benzyl alcohol in 300 ml of anhydrous tetrahydrofuran and 32 ml of tetramethylethylene diamine is added 183 ml of a 2.4 molar solution of n-butyl lithium in such a manner that the internal temperature of the reaction is maintained below 30°C. On completion of the addition, the reaction mixture is stirred at room temperature for 3 hours. The reaction mixture is then cooled to -70°C by means of a dry-ice/acetone bath, and 24 ml of ethyl pyruvate is added to the mixture over 1 minute. The reaction is then allowed to warm to room temperature and stirred overnight (18 hours). The reaction is then poured into an ice-water/ether mixture and the organic phase separated, dried over magnesium sulfate and the solvent evaporated under reduced pressure to yield ethyl-4-methyl-4H,6H-pyrrolo[l,2-a][4,l]benzoxazepine-4-carboxylate, MP 94°-96°C, which may be recrystallized from a mixture of ether-hexane (1 1). 

Dialkyl Ditellurium (from Phenylethynyl Alkyl Tellurium/Sodium Borohydride)4 To a solution of the alkyl phenylethynyl tellurium (2.0 mmol) in 10 ml ethanol at 0° (for primary alkyl groups) or 40° to 50° (for secondary alkyl groups) is added a solution of 81 mg (2.2 mmol) sodium borohydride in 3 ml ethanol. The pale yellow solution turns dark red. The solution is stirred for 10 min at O or 40° and then mixed with 0.5 ml of a 10% aqueous solution of sodium hydroxide. The mixture is cooled to 0° and stirred at 0 for 10 min. The mixture is diluted with 30 ml diethyl ether, then washed with brine, and the organic phase separated and... 

The Step 5 product (1.0 g) was dissolved in 15 ml water/methanol, 2 1, then treated with LiOil II2(), and stirred 2hours. The mixture was diluted with 2M HC1 and EtOAc and the organic phase separated. The solution was dried, concentrated, and 1.2 g product isolated, mp = 141 —142°C. 

The Step 6 product (0.3 g) and A,ALcarbonyldiimidazole (0.19 g) were dissolved in 20 ml DMF and stirred 1 hour at ambient temperature. The mixture was then treated with the Step 4 product (0.42 g) and 0.32ml triethylamine and stirred 20 hours. The solution was then diluted with water and diethyl ether, the organic phase separated, dried, and concentrated to a gum. The residue was purified by chromatography using CH2Cl2/methyl alcohol, 93 7, and 0.38 g product isolated, mp = 139—140°C. 

Sodium hydride (18.42 mmol) was suspended in 50 ml THF cooled to 0°C, then treated with triethylphosphonoacetate (19.30 mmol), and stirred 15 minutes. The mixture was further treated with fran -3,4-dimethylcyclopentanone (17.54 mmol) dissolved in 10 ml 1M tetrabutylammonium fluoride in THF, then stirred 2 hours at ambient temperature. The solution was then partitioned between 200 ml diethyl ether and 150 ml water and the organic phase separated and washed with brine. The solution was then dried with MgS04 and concentrated. The residue was purified by flash chromatography with silica gel using EtOAc/heptane, 1 9, and the product isolated in 94% yield as a colorless oil. 

To a suspension of cuprous iodide (0.03 mol) in 100 ml THF was added 25 ml dimethyl sulfide. The solution was cooled to -78 °C, phenyl magnesium bromide (0.06 mol) dissolved in diethyl ether added, stirred one hour, and 2-cyclohexenone (0.03 mol) dissolved in 10 ml THF added. The mixture was warmed to 0°C over 2 hours then re-cooled to -78 °C. It was treated with 15 ml hexamethyl-phosphoramide, stirred 30 minutes, treated with methyl cyanoformate (0.09 mol), and warmed to ambient temperature overnight. The mixture was poured into 100 ml 2M HCl, the organic phase separated, and the aqueous phase extracted with CH2CI2. The combined organic extracts were concentrated, the residue triturated with NH4CI, water, brine, dried, and 3.2 g product isolated as an oil. 

Triphasic reactions. For example, fluorous-organic-aqueous phases or two organic phases separated by a fluorous phase in a U-tube reaction flask. ... 

Although most UF/NF applications are aqueous, researchers have also indicated the feasibility of newer organic phase separations. The compatibility of membranes with different inorganic and organic solvents and feedstocks varies with the membrane materials. 

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