Syrups

HC CH(0H) CH20H. optically active. D-glyceraldehyde is a colourless syrup. May be prepared by mild oxidation of glycerol or by hydrolysis of glyceraldehyde acetal (prepared by oxidation of acrolein acetol). DL-glyceraldehyde forms colourless dimers, m.p. IBS-S C. Converted to methylglyoxal by warm dilute sulphuric acid. The enantiomers... 

C3H6O4, HO OCHCOHj-CH OH. An un-crystallizable syrup it occurs in optically active forms. Prepared by oxidation of glycerin with nitric acid. 

Obtained as a syrup from plants of the Solanaceae family. Intensely poisonous, its action resembles that of atropine. Sedative in small doses. 

Occasionally the solute may separate (particularly if strong external cooling is rapidly applied) as a metastable oil or syrup, which solidifies on standing although a considerable inten al may elapse before crystal-... 

Finally, add an excess of concentrated hydrochloric acid slowly with stirring to the alkaline filtrate remaining from the original reaction product. As the solution becomes acid, the sulphonyl-aniline separates as a thick sticky syrup which, when stirred, rapidly crystallises. Cool the mixture in ice-water if necessary, and then filter off the solid product at the pump, wash well with water, and drain. Recrystallise from a mixture of 2 volumes of ethanol and i volume of water to prevent the sulphonyl-aniline from separating as an emulsion, allow the hot solution to cool spontaneously (with occasional stirring) until crystallisation starts, and... 

Mix 6 2 ml. (6 4 g.) of pure ethyl acetoacetate and 5 ml. of pure phenylhydrazine in an evaporating-basin of about 75 ml. capacity, add 0 5 ml. of acetic acid and then heat the mixture on a briskly boiling water-bath (preferably in a fume-cupboard) for I hour, occasionally stirring the mixture with a short glass rod. Then allow the heavy yellow syrup to cool somewhat, add 30-40 ml. of ether, and stir the mixture vigorously the syrup may now dissolve and the solution shortly afterwards deposit the crystalline pyrazolone, or at lower temperatures the syrup may solidify directly. Note. If the laboratory has been inoculated by previous preparations, the syrup may solidify whilst still on the water-bath in this case the solid product when cold must be chipped out of the basin, and ground in a mortar with the ether.) Now filter the product at the pump, and wash the solid material thoroughly with ether. Recrystallise the product from a small quantity of a mixture of equal volumes of water and ethanol. The methyl-phenyl-pyrazolone is obtained... 

The use of impure reactants may give a deep red syrup and delay considerably tbe final solidification they should, therefore, be redistilled in a vacuum before use. 

A) Phenylhydrazones and 2,4-Dinitrophenylhydrazones (see 2 abo e). The latter are often to be preferred to phenylhydrazones because (a) the phenylhydrazones may separate as syrups, and also may decompose in hot solvents cf. p. 257), ( ) the 2,4 dinitrophenylhydrazones are often formed in the cold or with only brief warming, are much less soluble, and have higher m.ps. (p. 263). 

Physical properties. All are colourless crystalline solids except formic acid, acetic acid (m.p. 18 when glacial) and lactic acid (m.p. 18°, usually a syrup). Formic acid (b.p. loo ") and acetic acid (b.p. 118 ) are the only members which are readily volatile lactic acid can be distilled only under reduced pressure. Formic and acetic acids have characteristic pungent odours cinnamic acid has a faint, pleasant and characteristic odour. 

Some methiodides may separate inftially as sticky syrups in this case, redissolve a portion in ethanol and add to an ethanolic solution of prcric acid, when the yellow methopicrate is usually precipitated, and when filtered off and recrystallised, has often a sharp m.p. (M.ps., pp. 553-554.)... 

Saccharic acid. Use the filtrate A) from the above oxidation of lactose or, alternatively, employ the product obtained by evaporating 10 g. of glucose with 100 ml. of nitric acid, sp. gr. 1 15, until a syrupy residue remains and then dissolving in 30 ml. of water. Exactly neutralise at the boiling point with a concentrated solution of potassium carbonate, acidify with acetic acid, and concentrate again to a thick syrup. Upon the addition of 50 per cent, acetic acid, acid potassium saccharate sepa rates out. Filter at the pump and recrystaUise from a small quantity of hot water to remove the attendant oxahc acid. It is necessary to isolate the saccharic acid as the acid potassium salt since the acid is very soluble in water. The purity may be confirmed by conversion into the silver salt (Section 111,103) and determination of the silver content by ignition. 

To prepare crystalline monoperphthalic acid, place the thoroughly dry ethereal solution (4) in a distilling flask equipped with a capillary tube connected with a calcium chloride or cotton wool drying tube, and attach the flask to a water pump. Evaporate the ether without the application of heat (ice will form on the flask) to a thin syrup (about 150 ml.). Transfer the syrup to an evaporating dish, rinse the flask with a little anhydrous ether, and add the rinsings to the syrup. Evaporate the remainder of the ether in a vacuum desiccator over concentrated sulphuric acid about 30 g. of monoperphthalic acid, m.p. 110° (decomp.), is obtained. 

When dealing with esters of water-soluble, non steam-volatile, poly-hydric alcohols e.g., ethylene glycol or glycerol), the distillate consists of water only (density 1 00). The water soluble, non-volatile alcohol may be isolated by evaporation of the alkahne solution to a thick syrup on a water bath and extraction of the polyhydric alcohol from the salt with cold ethyl alcohol. 

You may have noticed that most soft drinks contain high fructose corn syrup Corn starch is hy drolyzed to glucose which is then treated with glu cose isomeraseto produce a fructose rich mixture The... 

FEEDS AND FEED ADDITIVES - RUMINANT FEEDS] (Vol 10) -for dextrose prod n [SYRUPS] (Vol 23)... 

Beet sugar molasses Beet-sugar syrup Behavior modification Behenic acid [112-85-6]... 

Corn starch [9005-25-6] Corn steep liquor Corn stover Corn sugar Corn sweetener Corn sweeteners Corn syrup... 

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