Chloroform-2-propanol

Some racemates (Figure 3.23) are more efficiently resolved on the bonded-type CSP than the coated-type CSP by using chloroform as a component of the eluent. On the bonded-type CSP of 24n, topologically interesting catenanes and molecular knots are successfully resolved using a hexane-chloroform-2-propanol mixture.185 The first direct HPLC resolution of the smallest chiral... 

Agbaba et al. [56] developed an HPTLC method for the determination of omeprazole, pantoprazole, and their impurities omeprazole sulfone and N-methylpantoprazole in pharmaceutical. The mobile phase chloroform-2-propanol 25% ammonia-acetonitrile (10.8 1.2 0.3 4), enables good resolution of large excesses of the drugs from the possible impurities. Regression coefficients (r > 0.998), recovery (90.7-120.0%), and detection limit (0.025-0.05%) were validated and found to be satisfactory. The method is convenient for quantitative analysis and purity control of the compounds. 

CPH Chloroform/2-propanol/ -heptane PFPA Pentafluoropropionic anhydride... 

A mixture of 2-bromo-4-methoxyacetanilide (244 mg, 1.0 mmol), di-chloro[l,4-bis(diphenylphosphino)butane]palladium(II) (30 mg, 0.05 mmol), and copper(II) oxide (80 mg, 1.0 mmol) in DMF (4 cm ) was stirred at 105-110 °C. After 1 min 4-trimethylstannyl-3-pyridinecarbaldehyde (405 mg, 1.5 mmol) dissolved in DMF (1 cm ) was added. After the halide was consumed (2 h), the reaction mixture was allowed to attain rt, the precipitate was filtered off and the filtrate was concentrated under reduced pressure. The residue was subjected to HPLC-chromatography using chloroform/2-propanol (95 5) as eluent. This gave 191 mg (91%) of the title compound mp 145-146 °C. 

Basic drugs (amphetamine, lidocaine, codeine, diazepam, methaqualone, etc. extracted by chloroform-2-propanol, 9 1 v/v)... 

Wyatt et al. worked out a GLC assay for atropine and scopolamine in belladonna extract. The extract was solved in 0.1 N sulphuric acid, homatropine hydrobromide was added to this solution as an internal standard, and interfering materials were extracted from the acidified solution with chloroform - and finally a mixture of chloroform and 2-propanol (10 3) if there is an emulsion problem. The alkaloids were subsequently extracted into chloroform (or chloroform-2-propanol) from the basified aqueous layer (pH 9.5 phosphate buffer was used instead of mineral alkali to minimize ester cleavage) and the chloroform extracts were filtered through anhydrous sodium sulphate (previously washed with chloroform). 87 % of the alkaloids were recovered in the first extract, so that two additional extractions gave suffi-... 

Sample mass 0.5 g solvent 98/2 (wt%) chloroform/2-propanol mixture solvent volume 10 ml irradiation time 30 min temperature 80 C... 

Extraction of the Alkaloids. Accurately weigh 250 mg of dried powdered plant material, and extract it with 5% aqueous acetic acid (20 ml, 18 h at room temp.). Filter the solution and add hexane (7 ml). The aqueous fraction is then made alkaline with ammonium hydroxide, and extracted with a 3 1 mixture of chloroform-2-Propanol (3 X 15ml) the pooled extracts evaporated to dryness under the reduced pressure the residue dissolved in 2.5 ml of MeOH and filtered through a RC 55, 0.45-pm membrane filter. 

Aliquots of 1 mL of plasma or urine samples are mixed with 1 mL of 1 M NaHC03 and 2 mL of distilled water and loaded onto a Sep-Pak cartridge. When blood is nsed, the mixture is centrifuged at 600 g for 8 min and the supernatant used for the next step. The sample solution is poured into the preconditioned cartridge at a flowrate of 5 mL/min. Sep-Pak cartridges are preconditioned with 10 mL of chloroform-2-propanol (9-1, v/v), 10 mL of acetonitrile, and 10 mL of distilled water. Then 10 mL of distilled water is added followed by 3 mL of chloroform-2-propanol (9-1, v/v) to elute the antidepressants. The eluate consists of an organic lower phase and an aqueous upper phase. The latter is discarded and the organic phase is evaporated to dryness. The residue is dissolved in 100 xL of methanol. 

In a novel application, carotenoids were separated on commercially available silica Chromarods P-carotene and other nonsaponflable lipids were chromatographed with a nonpolar mobile phase (light petroleum chloroform acetone, 89.5 10 0.5), and a more polar mobile phase (light petroleum chloroform 2-propanol, 50 40 10) was then used to resolve the xanthophylls canthaxanthin, lutein, violaxanthin, and neoxanthin (103). Quantitation was obtained by flame ionization detection, using methyl tetracosanoate as internal standard the working range was 0.6 to 5 pg P-carotene. The Chromarods themselves can be cleaned and reused. 

Many liquid mixtures exhibit a minimum boiling point (e.g. methanol and chloroform -propanol and water) whilst others show a... 

Elute the first fraction (neutral lipids) with 2 1 chloroform/propanol. 

A large number of electrocapillary measurements in amyl alcohol, phenol, furfural, ethyl acetate, aniline, chloroform, propanol, wobutanol and diethylether, and in binary and tertiary mixtures of these solvents with each other and with water are given in an early paper by Wild. ... 

Normal phase chromatography systems use a polar stationary phase with a nonpolar mobile phase. Generally, the packing materials within the normal phase columns are composed of unmodified silica spherical beads (cyano, amine, or diol packing materials can also be used) with the mobile phase consisting of nonpolar organic solvents such as ethanol, chloroform, propanol, or hexane. Table 4.3 outlines the main differences between typical normal phase packing materials. 

Mobile phase Chloroform-acetone (8 1) or ethyl acetate-benzene-chloroform-propanol (2 2 1 1). 

Bidimensional TLC studies have been done using silica gel as the sorbent. For instance, Lando et al. (1967) separated apurinic DNA oligonucleotides on silica gel with an isopropanol-water (75 25) mobile phase in the first direction and butanol-acetic acid-0.5% ammonia (90 30 40) in the second direction. Thymus DNA was separated into 21 spots, of which 16 were identified as nucleotides by UV spectrophotometry following enzymatic treatment. Issaq et al. (1977) used 2D-TLC on silica gel to separate a mixture of 19 adenine and uracil bases. Chloroform-methanol (90 10) was used for the first dimension and chloroform-propanol (90 30) for the second. 

Acetaldehyde reacts with phosphoms pentachloride to produce 1,1-dichloroethane [75-34-3] and with hypochlorite and hypoiodite to yield chloroform [67-66-3] and iodoform [75-47-8], respectively. Phosgene [75-44-5] is produced by the reaction of carbon tetrachloride with acetaldehyde in the presence of anhydrous aluminum chloride (75). Chloroform reacts with acetaldehyde in the presence of potassium hydroxide and sodium amide to form l,l,l-trichloro-2-propanol [7789-89-1] (76). 

The para and ortho positions of phenols condense at the carbonyl group of acetone to make bisphenols, eg, bisphenol A, 4,4 -(l-methylethyhdene)bisphenol [80-05-07]). If the H atom is activated, CICH— compounds add to the carbonyl group in the presence of strong base chloroform gives chloretone (l,l,l-trichloro-2-methyl-2-propanol [57-15-8]). 

Fractional extraction has been used in many processes for the purification and isolation of antibiotics from antibiotic complexes or isomers. A 2-propanol—chloroform mixture and an aqueous disodium phosphate buffet solution are the solvents (243). A reciprocating-plate column is employed for the extraction process (154). 

Metformin. Metformin [657-24-9] (1,1-dimethylbiguanide), mol wt 129.17, forms crystals from propanol, mp 218—220°C, and is soluble in water and 95% ethanol, but practically insoluble in ether and chloroform. Metformin, an investigational dmg in the United States, does not increase basal or meal-stimulated insulin secretion. It lowers blood glucose levels in hyperglycemic patients with Type II diabetes but has no effect on blood glucose levels in normal subjects. It does not cause hypoglycemia. Successful metformin therapy usually is associated with no or some weight loss. 

Contaminants and by-products which are usually present in 2- and 4-aminophenol made by catalytic reduction can be reduced or even removed completely by a variety of procedures. These include treatment with 2-propanol (74), with aUphatic, cycloaUphatic, or aromatic ketones (75), with aromatic amines (76), with toluene or low mass alkyl acetates (77), or with phosphoric acid, hydroxyacetic acid, hydroxypropionic acid, or citric acid (78). In addition, purity may be enhanced by extraction with methylene chloride, chloroform (79), or nitrobenzene (80). 

Condensation of vinyl chloride with formaldehyde and HCl (Prins reaction) yields 3,3-dichloro-l-propanol [83682-72-8] and 2,3-dichloro-l-propanol [616-23-9]. The 1,1-addition of chloroform [67-66-3] as well as the addition of other polyhalogen compounds to vinyl chloride are cataly2ed by transition-metal complexes (58). In the presence of iron pentacarbonyl [13463-40-6] both bromoform [75-25-2] CHBr, and iodoform [75-47-8] CHl, add to vinyl chloride (59,60). Other useful products of vinyl chloride addition reactions include 2,2-di luoro-4-chloro-l,3-dioxolane [162970-83-4] (61), 2-chloro-l-propanol [78-89-7] (62), 2-chloropropionaldehyde [683-50-1] (63), 4-nitrophenyl-p,p-dichloroethyl ketone [31689-13-1] (64), and p,p-dichloroethyl phenyl sulfone [3123-10-2] (65). 

In the presence of an alkali metal hydroxide at about 50°C, chloroform condenses with acetone to give l,l,l-trichloro-2-methyl-2-propanol, [57-15-8] ie, chlorobutanol, chloretone, or acetone—chloroform (9,10). Chlorobutanol is a white crystalline substance with a campborlike odor its sedative, anesthetic, and antiseptic properties have given the compound some importance in the pharmaceutical industry. 

Water with ethanol, n-propanol and isopropanol, tcrt-butanol, propionic acid, butyric acid, pyridine, methanol with methyl iodide, methyl acetate, chloroform,... 

The layer was prewashed by developing once in chloroform and then twice in toluene — 2-propanol (10 + 1), with drying at 110°C for 30 min after each step. 

The methacrylic backbone structure makes the spherical Toyopearl particles rigid, which in turn allows linear pressure flow curves up to nearly 120 psi (<10 bar), as seen in Fig. 4.45. Toyopearl HW resins are highly resistant to chemical and microbial attack and are stable over a wide pH range (pH 2-12 for operation, and from pH 1 to 13 for routine cleaning and sanitization). Toyopearl HW resins are compatible with solvents such as methanol, ethanol, acetone, isopropanol, -propanol, and chloroform. Toyopearl HW media have been used with harsh denaturants such as guanidine chloride, sodium dodecyl sulfate, and urea with no loss of efficiency or resolution (40). Studies in which Toyopearl HW media were exposed to 50% trifluoroacetic acid at 40°C for 4 weeks revealed no change in the retention of various proteins. Similarly, the repeated exposure of Toyopearl HW-55S to 0.1 N NaOH did not change retention times or efficiencies for marker compounds (41). 

A solution of 0.1 mol of 1-cyclohexylamino-2-propanol in 30 grams of chloroform was saturated with dry hydrogen chloride gas, with cooling. A solution of 0.1 mol of benzoyl chloride in 30 grams of chloroform was added and the solution was heated in a bath at 50° to 55°C for four days under a reflux condenser protected from atmospheric moisture. Then the solvent was removed by vacuum distillation while the mixture was warmed on a water bath. Benzene was then added to the syrupy residue and the reaction product crystal lized out after the benzene was removed by vacuum distillation. 

Interestingly, the diastereofacial selectivity can be reversed in the Strecker reaction of aldimines derived from galactosylamine 1 by simply changing the solvent. When the reaction of trimethylsilyl cyanide with the Schiff bases 2 catalyzed by zinc chloride, is carried out in chloroform instead of 2-propanol, there is a preferred formation of the (.S)-amino nitrile diastereomers63. 

Mobile phase Chloroform - 1-propanol - formic acid (50+10+5)... 

The checkers dried the product in a vacuum desiccator for 24 hours to remove all the 2-propanol and obtained 77-79 g. (64-66%), m.p. 70-72°. The yield reported by the submitters was 82-89 g. (68-74%), m.p. 73—74°. The literature melting point is 66-67°. The product has the following spectral properties 90-MHz. proton magnetic resonance (chloroform-d) d (multiplicity, number of protons, assignment, coupling constant J in Hz.) 2.84... 

PtRu nanoparticles can be prepared by w/o reverse micro-emulsions of water/Triton X-lOO/propanol-2/cyclo-hexane [105]. The bimetallic nanoparticles were characterized by XPS and other techniques. The XPS analysis revealed the presence of Pt and Ru metal as well as some oxide of ruthenium. Hills et al. [169] studied preparation of Pt/Ru bimetallic nanoparticles via a seeded reductive condensation of one metal precursor onto pre-supported nanoparticles of a second metal. XPS and other analytical data indicated that the preparation method provided fully alloyed bimetallic nanoparticles instead of core/shell structure. AgAu and AuCu bimetallic nanoparticles of various compositions with diameters ca. 3 nm, prepared in chloroform, exhibited characteristic XPS spectra of alloy structures [84]. 

Fig. 3. Stepwise synthesis of rifaximin (from De Angelis [39]). The reaction of rifamycin S (I) with pyridine perbro-mide (II) in 2-propanol/chloroform (70/30) mixture at 0°C gives 3-bromorifamycin S (III), which is then condensed with 2-amino-4-methyl-pyridine (IV) at 10°C. The o-quinonimic compound (V) is then obtained. This compound is finally reduced with ascorbic acid to rifaximin. 

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