10 -Camphor sulphonate

Using an electrohydrodynamic processing method, a polyurethane-based core was coated with a polyanihne shell to produce stable aqueous emulsions. Using a chiral dopant, (lS)-(H-)-10-camphor sulphonic acid (HCSA) induced a high degree of optical activity in the particles. Dispersions of highly optically active colloids could be prepared both with and without polystyrenesulphonate. In both cases, the optical activity increased on standing after polymerisation. Particle size increased with polymerisation time. 16 refs. 

Many racemic mixtures can be separated by ordinary reverse phase columns by adding a suitable chiral reagent to the mobile phase. If the material is adsorbed strongly on the stationary phase then selectivity will reside in the stationary phase, if the reagent is predominantly in the mobile phase then the chiral selectivity will remain in the mobile phase. Examples of some suitable additives are camphor sulphonic acid (10) and quinine (11). Chiral selectivity can also be achieved by bonding chirally selective compounds to silica in much the same way as a reverse phase. A example of this type of chiral stationary phase is afforded by the cyclodextrins. 

There are two chiral centres In (47) so a mixture of diastereoisomers is produced in 75 and 15% yields. Fortunately the major isomer is the analgesic. In fact only one enantiomer of this diastereo isomer is analgesic and so (48) is resolved with camphor sulphonic acid before esterification. The other enantiomer is a useful cough suppressant. 

Paper Chromatography too has been employed. The paper was impregnated with a solution of (+) camphor sulphonic acid or it was used as such unimpregnated, because paper itself is optically active. 

The 1-dichloro-d-bromo-camphor sulphonie salts are the least soluble. The colour of these optically active derivatives is the same as that of the racemic salts. 1-Dichloro-diethylenediamino-chromie d-a-bromo-camphor sulphonate, [Cren2Cl2]SO3C10H14OBr, forms small, shining violet crystals, and has specific rotation [molecular rotation of [M]D + 176-9°. Solutions of both isomers are rapidly raeemised. 

The diehloro-salts are obtained from the camphor sulphonate by the action of hydrochloric acid. 

The resolution was carried out by means of d-bromo-camphor-sulphonie acid. The salts of the bromo-series are more easily resolved on account of the great difference between the isomeric d-bromo-camphor sulphonates. In both series the d-bromo-eamphor sulphonate of the d-isomer is more sparingly soluble. These active compounds are very stable, and aqueous solutions of the bromides of the bromo-ammine series may be kept for a considerable time at ordinary temperatures, and even on heating to boiling racemisation does not occur. If the bromine in the complex be removed by means of silver nitrate activity... 

In 1913 Werner 2 described a new series of optically active cobalt compounds containing two asymmetric cobalt atoms in the molecule, the tetraethylenediamino-/i-amino-nitro-dicobaltic salts. The resolution is effected by treating tetraethylencdiamino - /x - amino - nitro-dicobaltic bromide with silver d-bromo-camphor sulphonate and fractionally crystallising the product. 

Three different d-bromo-camphor sulphonates are obtained, namely, (1) an inactive crystalline salt containing eight molecules of water of hydration, from which a series of hevo-salts can be prepared (2) an active crystalline form with seven molecules of water of hydration, yielding a series of meso-salts and (3) another active form with six molecules of hydration, yielding a series of dextro-salts. 

Tetraethylenediami.no - - amino - nitro - dicobaltic d-bromo-camphor Sulphonate,... 

The nitrate is transformed into the bromide, and this is then treated with active silver bromo-camphor sulphonate. A dark green solution is formed, and a difficultly soluble bromo-camphor sulphonate mixed with silver salt. This mixture is extracted with hot water and the solution so obtained fractionally crystallised. The resolution is tedious and the yield is not good. 

Optically Active Dodecammino-hexol-tetra-cobaltic Salts.3— These salts may be resolved by means of bromo-camphor sulphonic acid. Dodecammino-hexol-tetracobaltic chloride is mixed with silver bromo-camphor sulphonate, whereby all the chlorine is precipitated as silver chloride and the solution treated with dilute acetic acid. The ilrst crop of d-bromo-camphor sulphonate is laevo-rotatory, that from 1-bromo-eamphor sulphonate dextro-rotatory. 

Salts have been prepared with optically active camphor sulphonic acids. These also are yellow crystalline bodies, but no resolution of the base has been effected. d-Camphoric acid, d-tartaric acid, and d-nitro-camphor compounds were also prepared, and again no resolution was effected. Hence it is concluded that the hydroxo- and nitroso-groups are probably in the 1-, 0-, or trans-position. 

Two series of complex iridium salts corresponding to the hexammino-and diacido-iridium salts have been prepared containing ethylene-diamine. These have the same general characteristics as the ammino-salts. Both series have been resolved into optically active isomers, the dinitrito-series by means of d- and 1-bromo-camphor sulphonic acid, and the triethylenediamino-series by d- and 1-nitro-camphor. Attempts have been made to prepare etliylenediamino-derivatives containing tetravalent iridium. Thus, sodium hexaehloro-iridate, [IrCl6]Na2, reacts with ethylenediamine, but the products are syrupy and cannot be purified. Derivatives of trivalent iridium, however, have been prepared. These are crystalline and fairly easily purified. The... 

The bromo-camphor sulphonate, [Ir en2(NO2)2][d-C10H14O4BrS], is prepared by treating the iodide with silver bromo-camphor sulphonate. It separates as a vitreous mass. 

Theoretically two dinitro-series are possible, but only one has been obtained, and, as the bromo-camphor sulphonate is separable into two optically active components, the series prepared is regarded as the cis-, or 1-, 2-series. 

Dinitrito-diethylenediamino-iridium 1-camphor Sulphonate gives rotation [o.]d— 26°. 

Triethylenediamino-iridium Salts, [Iren3]R3.—From the mother-liquor after crystallisation of dinitro-diethylenediamino-iridium d-camphor sulphonate, the d-camphor sulphonate of racemic triethylene-diamino-iridium crystallises. 

Mobile phase butane, pentane, hexane, octane, or camphor-sulphonate (Na salts) in MeOH-H20-ACN or ACN-H20, pH = 3.0. 

Resolution was effected by treatment with the silver salt of d-camphor-sulphonic acid and subsequent decomposition of the camphor-sulphonate formed, by means of potassium iodide ... 

The solubility of the electrically conductive form, the protonated EM salt, is poor in common solvents, and so, initially, EM base was used to form films from NMP solution before conversion to the salt with HC1. Attempts to increase solubility by incorporating pendent alkyl chains were counterproductive as such polymers had significantly lower electrical conductivity. Better solubility is obtained for salts produced with sulphonic acids. Thus the camphor sulphonic acid salt dissolves in m-cresol and the 2-acrylamido-2-methyl-l-propanesulphonic acid salt dissolves in dichloro-acetic acid. The use of these systems, and polymer synthesised below room temperature, has facilitated the spinning of fibres with oriented polymer chains and conductivity along the fibre as high as 2x 105f2-Im-1 (Pomfret et ai, 1998). 

By measuring the conductance of several picrates in di-wopropyl ketone at different concentrations, it was shown by the method of Fuoss and Kraus 6 that up to concentration of 01 M there is no detectable triple ion formation. Thus concentrations high enough to satisfy condition (ii) are attainable without the formation of multiple ions. The results of semi-quantitative preliminary experiments indicated that tetraethylammonium and picrate ions had nearly the same mobility in di-wopropyl ketone. This was confirmed by measuring the transport number of the picrate ion by the moving-boimdary method. The conditions for the successful use of the moving-boundary method have been fully examined by Longsworth and Maclnnes.7 A simplified apparatus was used and is shown in fig. 3 camphor-sulphonate was found to be a suitable indicator ion. 

Materials. An aqueous solution of tetraethylammonium camphor-sulphonate was prepared by neutralizing camphor-sulphonic acid with the hydroxide. This solution was evaporated to dryness under reduced pressure, and the salt was purified by recrystallizing from benzene. 

The whole apparatus except the cathode compartment was rinsed out with the prepared picrate solution. The tube containing the mercury and mercurous picrate paste was introduced into the anode compartment, which was then filled with picrate solution from the reservoir. When the anode compartment and U-tube were completely full the anode connector was put in position and the apparatus was clamped in a thermostat, so that the tap was just above the surface of the liquid. After the filled part of the apparatus had reached the temperature of the thermostat, the reservoir was emptied via the cathode compartment both these were then washed with alcohol and dried by suction. The cathode, which consisted of a piece of platinum gauze surrounded by solid tetraethylammonium camphor-sulphonate, and the inner tube B were put in position and the cathode... 

Phenylbenzylethyl-n-propylarsonium iodide, (CgHj)(CeH5CH2) (C2H6)(C3H7)AsI, is formed firom phenylethyl- i-propylarsine and benzyl iodide by heating at 40° to 50 C. It separates from dilute alcohol in colourless crystals, M.pt. 128° C. Its d-camphor- -sulphonate shows no signs of resolution into optically active components. 

Strong and weak bases, catecholamines Alkyl and aryl sulphonates e.g. camphor sulphonic acid, and alkylsulphates (e.g. lauryl sulphate) which show different selectivity... 

Phenol chromium tricarbonyl complex, n-butyllithium (2,mols) tertramethylethylenediamine (3 mols.) in THF at 60C for 3h. Benzaldehyde added and after oxidative decomplexation by addn. of Ij and camphor sulphonic acid in 10%HC/THF l-(3-hydroxyphenyl)benzyl slcohol obtained. 

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