Mannitol chemical production

G. Polyetherpolyole F. polyetherpolyols P. carry hydroxylic groups to be reacted with di/tri-isocyanates for producing polyurethanes, such as thermoplasts, - coatings, elastomers and foams. Traditional starting materials for p. are glycol and the RR-based ->glycerol, - sucrose, ->dextrose, - sorbitol, - sucrose molasses, xylitol, - mannitol, and products of hydrogenolysis of sucrose (- sucrose, chemical modifications). 

A case report of acute arsine poisoning in which a 27-y-old man was exposed to arsine during chemical manufacturing was reported by Pinto (1976). The subject was exposed to arsine as a result of arsine production via a reaction between a galvanized bucket and an arsenic-containing sulfuric acid solution. The exposure (duration not specified) produced toxic effects characterized by abdominal cramping, thoracic discomfort, and hematuria. Over the next week, the patient s hematocrit declined from 42.5 to 27.1 and hemoglobin dropped from 14.1 to 9.5 g/dL even with medical intervention (blood transfusions and mannitol diuresis). Nine hours after exposure, blood arsenic was 159 g/dL and urinary arsenic was 1862 ug/L. 

U.S. 6,649,754 (to Merck) describes a process for making mannitol by hydrogenation of a mixture of glucose and fructose. U.S. 3,632,656 (to Atlas Chemical) describes recovery of mannitol from a mixture with sorbitol by crystallization from aqueous solution. U.S. 4,456,774 (to Union Carbide) describes an adsorptive separation of mannitol from sorbitol. U.S. 6,235,947 (to Takeda Chemical Industries) describes a process for recrystallizing mannitol to improve the crystal morphology and hence make a more compressible product that can be used in making tablets. Estimate the cost of production of Mannitol by the Merck route and determine which separation is most economical. What is the additional cost of making the recrystallized product via the Takeda route ... 

Purely chemical processes, such as the oxidation of D-mannitol by chlorine, normally result in a mixture of D-mannose and D-fructose, but the ratio can be appreciably shifted in favor of either of these products. Indeed, prolonged treatment (3-5 days) at low temperatures gives D-mannose in good yield, whereas several short periods (1 day) afford D-fructose exclusively. After nine chlorinations of 1 day, at 4 to 20°, 53% of the hexitol is oxidized and 49% thereof is converted into D-fructose. A theoretical yield is afforded by the photochemical oxidation of D-mannitol. When a small quantity of D-fructose is added to a much greater amount of zinc oxide and exposed to the effects of air and sunlight, D-mannose and D-fructose are formed in amounts almost proportional to the amount of sunlight. It may be concluded that an effort has been made to find a cheap source for preparation of D-fructose and to lower the production costs by use of easier isolation and purification procedures. Of the various methods presented, the isomerization reaction is certainly the most promising. 

Parenteral formulations often contain excipients considered to be chemically stable and inert however, all excipients in a formulation may influence the photochemical stability of the product. Dextrose and sodium chloride are used to adjust tonicity in the majority of parenteral formulations. Sodium chloride can affect photochemical processes by influencing solvation of the photoreactive molecules (see Section 14.2.3). The ionic strength is reported to affect the photochemical decomposition rate of minoxidil until a saturation level is reached (Chinnian and Asker, 1996). The photostability of L-ascorbic acid (vitamin C) in aqueous solution is enhanced in the presence of dextrose, probably caused by the scavenging effect of the excipient on hydroxyl radicals mediated by the photolysis of ascorbic acid sucrose, sorbitol, and mannitol have the same effect (Ho et al., 1994). Monosaccharides (dextrose, glucose, maltose, and lactose), disaccharides (sucrose and trehalose), and polyhydric alcohols (inositol, mannitol, and sorbitol) are examples of commonly used lyo-additives in parenterals. These excipients may also affect photochemical stability of the products after reconstitution. 

R) -1 sopropylideneglycerol is a useful C3-synthon in the synthesis of (S)-P-blockers, e. g. (S)-metoprolol. Also, (R)-isopropylideneglyceric acid may be used as the starting material for the synthesis of biologically active products. The resolution is carried out by selective microbial oxidation of the (S)-enantiomer (Fig. 19-9). The chemical synthesis of (R)-isopropylideneglycerol starts either from unnatural L-mannitol or from L-ascorbic acid (Fig. 19-10). In comparison to the biotransformation, here stoichiometric quantities of lead tetra acetate are needed. 

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