Drying glycerol

Before the final assembling of the apparatus, the flasks are charged as follows One kilo of freshly fused and finely powdered acid potassium sulfate, 200 g. of powdered potassium sulfate, and 300 g. of dry glycerol (Note 3) are thoroughly mixed in each of flasks B and D. In each of flasks I and M is placed about i g. of hydroquinone to act as a stabilizer for the acrolein (Moureu, Compt. rend., 170, 26 (1920)). 

The product in M is treated with small amounts of solid sodium bicarbonate to neutralize any acid present. The cold liquid is filtered through a small filter into a 1500-cc. distilling flask containing about i g. of hydroquinone. It is then distilled into a tared dark bottle containing about i g. of hydroquinone. The yield of product boiling at 52.5-55.5° (Note 5) obtained from 1200 g. (13 moles) of dry glycerol is 240-350 g. (33-48 per cent of the theoretical amount). 

Dry glycerol (5.53 g, 60 mmol) and dibutyltin oxide (14.94 g, 60 mmol) in 120 mL of toluene were refluxed for 4 h under argon. The theoretical amount of water was collected in a Dean-Stark sidearm. The reaction mixture was cooled to 70 C and 4-chloromethyl-l,3-dioxolane-2-thione (5 9.16 g, 60 mmol) (7) was added to the cyclic tin compound 4 in one portion. After 5 h, the solvent was removed under reduced pressure to leave a two-phase liquid residue. The dibutyltin sulfide by-product was removed by several extractions with hexane to provide the crude chloromethyl-hydroxy-substituted oxaspiro intermediate 6 as a pale yellow oil in 99% yield. 

Dry glycerol (10 mg) is treated with 60 rl of 0.3 M HCl in dry acetone and 4 mg of powdered anhydrous sodium sulphate, and the mixture is shaken at intervals over a... 

The microwave-assisted synthesis of 2-cyanomethylfhiazoles 156 was effectively carried out using bromoaceto-phenones and 2-cyanoacetamide in anhydrous glycerol (Scheme 94) [138]. It was found thaf dry glycerol should be used to avoid formation of amides as by-products. 

Glycerol ct-dichlorohydrin, sym-dichloroiso-propyl alcohol, 1,3-dichloro-2-hydroxypropane, CH2CI-CHOH-CH2C1. Colourless liquid with an ethereal odour b.p. 174-175" C. Prepared by passing dry HCl into glycerin containing 2% elhanoic acid at 100-1 lO C. Converted to x-epichlorohydrin by K.OH, Used as a solvent for cellulose nitrate and resins. 

Water-Based Writing Inks. These consist of very fine pigment dispersions in aqueous media containing small amounts of glycol or glycerol and a dispersing aid. They dry mainly by evaporation and quick wetting of ceUulosic fibers in paper substrates. 

Humectants such as propylene glycol, glycerol, sorbitol, or calcium chloride can prevent drying and caking. 

Physical Properties. Sodium metabisulfite (sodium pyrosulfite, sodium bisulfite (a misnomer)), Na2S20, is a white granular or powdered salt (specific gravity 1.48) and is storable when kept dry and protected from air. In the presence of traces of water it develops an odor of sulfur dioxide and in moist air it decomposes with loss of part of its SO2 content and by oxidation to sodium sulfate. Dry sodium metabisulfite is more stable to oxidation than dry sodium sulfite. At low temperatures, sodium metabisulfite forms hydrates with 6 and 7 moles of water. The solubiHty of sodium metabisulfite in water is 39.5 wt % at 20°C, 41.6 wt % at 40°C, and 44.6 wt % at 60°C (340). Sodium metabisulfite is fairly soluble in glycerol and slightly soluble in alcohol. 

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