Alcoholic crystallization

Sahcyl alcohol [90-01-7] (saligenin, o-hydroxybenzyl alcohol) crystallizes from water in the form of needles or white rhombic crystals. It occurs in nature as the bitter glycoside, saUcin [138-52-3] which is isolated from the bark of Salix helix S. pentandra S. praecos some other species of willow trees, and the bark of a number of species of poplar trees such as Folpulus balsamifera P. candicans and P. nigra. 

The corresponding dihydrochloride is prepared by dissolving this base in about twice its weight of alcohol, by treating it with excess of gaseous HCI and by precipitating it with ether. The solvent is decanted and the residue, dissolved in a minimum of alcohol, crystallizes on the addition of ether, MP 193°C. 

The acid, without drying, is suspended in about 200 cc. of distilled water and with vigorous stirring, cautiously (Note 3) treated with 25 per cent sodium hydroxide solution until dissolved and the solution reacts neutral to litmus. The solution is then filtered through folded filter paper which should be free from soluble calcium salts, otherwise the filtrate will remain clouded by a suspension of the calcium salt. The clear, faintly yellow or colorless filtrate is then vigorously stirred and treated with 1.5 volumes of 95 per cent alcohol. Crystallization is induced by rubbing with a rod and then an additional volume of alcohol is added. The mixture should be allowed to cool to about 200 and stand for at least two hours to complete the precipitation of the salt, which is then filtered by suction and washed thoroughly with 85 per cent alcohol. The salt is then air-dried. The yield is 73-77 g. (38-40 per cent of the theoretical amount). 

Evaporation of the water gave a partially crystalline mass which was dissolved in methanol. Evaporation of the methanol yielded a thick paste, from which more solvent was removed by pressing it between filter paper. After several repetitions of this procedure the product sintered somewhat about 100°, but had no sharp melting point. It was then recrystaliized by evaporation of solvent from its solution, first in alcohol and then in acetic acid. The crystalline material thus obtained melted at 113-114.5° and gave good analytical values, but a purer product resulted from the treatment of a methanolic solution of this material with enough ether to form a second layer. A reddish flocculent precipitate was separated and after evaporation of the alcohol, crystals melting at 116-117.5° were obtained. 

The reaction was extracted twice with 5 L heptane. The organic layers were then combined, washed with 2.5 L water and evaporated by distillation until the alcohol product concentration was 200 gL. The solution was cooled to 35 °C and seeded with 1 g alcohol product prior to aging for 1 h and then cooling again to —10 °C. The alcohol crystallized into a solid with >99% purity. 

Two methods are employed industrially to produce crystalline fructose, aqueous crystallization and alcoholic crystallization. Yields of fructose crystallized from water syrups are only of the order of 50%, due to the very high water solubility of the sugar, while the high viscosity of the concentrated solution results in long crystallization times, typically 50 hours or more (2). The second process requires the addition of lower alcohols (eg. ethanol) to a concentrated fructose syrup, generally 90% total solids or more, at temperatures of 50 C to 80""c and then cooling to cause crystallization. Fructose yields are from 70 to 80% and the total time involved is 8 to 12 hours (3). However, large quantities of... 

Polar O—H bonds are found in molecules such as water and alcohols. Crystal structures of several crown ether complexes have indicated that the cavity need only be partially filled by water.260-262 Several host-guest complexes of alcohols with the pyridino crown (83) have been reported.263 Longer chain and branched alcohols do not in general form crystalline adducts with this ligand. 

Practical advantage of the method is that it does not require dry solvents. The resolving agent can be prepared by simple solution of DBTA monohydrate and half an equivalent amount of calcium oxide in hot 95 % ethyl alcohol. Crystallization of the diastereoisomeric coordination complex can be achieved by cooling and addition of cosolvents (e.g. acetone, toluene, ethyl acetate, etc.) or change ethyl alcohol to an ester type solvent. The enantiomers can be liberated from the crystalline complex by simple acidic workup procedure. [23]... 

An amount of 40 g. of 2,3,4,6-tetra-O-acetyl-a-D-glucosyl bromide is warmed with 12 g. of diethylamine in 20 ml. of dry benzene at 60° until dissolved. (Benzene is often replaced by chloroform, and the initial warming is often omitted.) After 32 hours at room temperature, the reaction mixture is extracted with dry ether, and the diethylamine hydrobromide is removed by filtration. The filtrate is washed once with dilute sulfuric acid and twice with water and is dried over calcium chloride. After evaporation of the ether under diminished pressure, the residue is dissolved in the least possible amount of hot alcohol. Crystallization occurs after the addition, with stirring, of petroleum ether to the cooled solution. Yield of crude 2,3,4,6-tetra-0-acetyl-(2-hy-droxy-D-glucal), 17 g. (51% of the theoretical). Itecrystallization is effected from hot water or from ethanol with the addition of water to turbidity.1 2... 

The codeine that occurs naturally in small amounts in opium is isolated from the aqueous morphine alkaloid mother liquors by immiscible extraction with a nonaqueous solvent. Dilute sulfuric acid is employed to extract the codeine sulfate from the nonaqueous solvent. This solution is evaporated, crystallized, and recrystallized. The alkaloid is precipitated from a sulfate solution by alkali and purified, if necessary, by alcoholic crystallization. It is converted into the phosphate by solution in phosphoric acid, evaporation, crystallization, centrifugation, and drying. 

The procedure as given is generally applicable for the reduction of esters to alcohols in excellent yields. When preparing the solid normal saturated alcohols, the procedure may be modified, if desired, to permit the recovery of the acid from the unreduced ester. After the alkali is removed the alcohol layer is washed with two successive portions of 20 per cent salt solution which are discarded. Neither the strong alkali nor the salt solutions remove an appreciable amount of organic acid. A solution of 50 g. of calcium chloride in 150 cc. of water is added to the butyl alcohol solution, the mixture is steam-distilled until the butyl alcohol is removed, and the flask and contents are allowed to cool. A hole is made in the cake of solid alcohol and the water layer removed. Two liters of toluene is added and the flask warmed and shaken until the alcohol dissolves and only fine crystals of the calcium salt of the unreduced acid remain. The solution is cooled to 350 and filtered with suction. The calcium soap is removed from the filter, warmed with about 500 cc. of toluene, cooled, filtered, and washed with a little more toluene. The combined toluene solutions may be concentrated and the alcohol crystallized, or the toluene may be completely distilled and the residue vacuum distilled. The insoluble calcium... 

Studies were carried out both with chiral ethanol and chiral neopentanol. " Figure 12 shows the anionic phthalate half-ester of (-F)-neopentyl-l- f alcohol crystallized as its strychnine salt. In this study the absolute configuration of the -0-CHD-C(CH3)3 group was determined to be (S) (Figure 12). 

Terpine. Leave oil of turpentine for a lon time in contact with a mixture of nitric acid and alcohol. Crystals of terpine form. By boilinit an aqueous solution of ter pine with a sm quantity of eniphuric or other acid, terpinole is formed, and may be separated by distillation. It has the odor of hyacinths. 

On evaporation of an aq soln, the free acid dec into sulfuric add and -naphthol. However, very coned solns of the acid can be obtained. The normal sodium salt is sol in wa ter, and readily sol in alcohol crystallizing with 2 mols of alcohol. Ref Forster, Keyworth, loc. cit. 

Two processes at 310°K. (102 c.p.s.) and 350°K. (102 c.p.s.) have been found (68), using the dielectric technique, for atactic poly (vinyl alcohol) crystals, grown from 0.05% triethylene glycol solution while cooling from 180° to 165°C. These maxima have been previously attributed (77) to local mode and glass transformation motion, respectively. 

Schulze and Trier discovered betonicine, C7H13O3N, in Betonica officinalis L. and in Stachys sylvatica L. (43, 58). This alkaloid has a sweet taste, a neutral reaction and is readily soluble in water but difficultly so in cold alcohol. Crystallization from this latter solvent yields short, four-sided, truncated pyramids containing a molecule of water of crystallization, C7H13O3N H2O. These crystals, after drying, melted at 252° (dec) (59) and at temperatures in excess of this produced a vapor which shows an intense pyrrole reaction. It is optically active, [a ]D 36.6° (water), and forms salts readily. The hydrochloride separates from ethanol as colorless prismatic needles, m.p. 224° (dec) [a]J —24.8° (water), the chloroaurate, clusters of small yellow tablets, melts at 230-232° (dec) and the chloroplatinate, (B HCLjPtCU, melts at 225-226° (dec). 

Blue-violet, fine crystalline powder. d 1.468. Heat of formation —16.3 kcaL/mole. The decomposition pressure at 176.5°C is 1 atm. Decomposes in HgO, liberating NH3. Soluble in aqueous ammonia not soluble in cone, ammonia or alcohol. Crystal structure J11 type. 

Kawahata, M., Yamaguchi, K. and Ishikawa, T. (2005) o-Bisguanidinobenzene, a powerful hydrogen acceptor crystal structures of organic complexes with benzoic acid, phenol and benzyl alcohol. Crystal Growth Design, 5, 373-377. 

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