Glycols preparation

Figure 16.2 is the mass spectrum of propylene glycol and shows the presence of an abundant m/z 45 ion. A library search will provide strong evidence that this compound is propylene glycol. Preparation of a TMS derivative will confirm this assignment. 

How can you make a polyester and a polyamide Objectives Prepare a polyester from phthalic anhydride and ethylene glycol. Prepare a polyamide from adipoyl chloride and hexamethylenediamine. phthalic anhydride (2.0 g) sodium acetate (0.1 g) ethylene glycol (1 mL) 5% adipoyl chloride in cyclohexane (25 mL) 50% aqueous ethanol (10 mL) 5% aqueous solution of hexamethylenediamine (25 mL) 20% sodium hydroxide (NaOH) (1 mL) scissors copper wire test tube test-tube rack 10-mL graduated cylinder 50-mL graduated cylinder 150-mL beakers (2) ring stand clamp Bunsen burner striker or matches balance weighing papers (2)... 

Imidazole carboxylates of polyethylene glycols prepared with CDI react with amines to give polyethylene glycols (PEG) with carbamate end groups.12071 For example, PEG-... 

Menna E, Scorrano G, Maggini M, Cavallaro M, Della Negra F, Battagliarin M, Bozio R, Fantinel F, Meneghetti M (2003) Shortened single-walled nanotubes functionalized with polyethylene glycol) preparation and properties. Arkivoc 64-73. 

Bolhuis, G.K. Arends-Scholte, A.W. Stuut, G.J. de Vries, J.A. Disintegration efficiency of sodium starch glycolates, prepared from different native starches. Eur. J. Pharm. Bio-pharm. 1994, 40 (5), 317-320. 

Gebre-Mariam, T. Winnemoller, M. Schmidt, P.C. An evaluation of the disintegration efficiency of a sodium starch glycolate prepared from enset starch in compressed tablets. Eur. J. Pharm. Biopharm. 1996, 43 (2), 124-132. Parrott, E.L. Comparative evaluation of a new direct compression excipient, soludex 15. Drug Dev. Ind. Pharm. 1989, 15, 561-583. 

Gebre Mariam T, Winnemoller M, Schmidt PC. Evaluation of the disintegration efficiency of a sodium starch glycolate prepared from enset starch in compressed tablets. Eur J Pharm Biopharm 1996 42(2) 124-132. 

Lin, Y.-S. Hlady, V. Golander, C.-G., The surface density gradient of grafted poly(ethylene glycol) preparation, characterization and protein adsorption, Colloids Surf. B Biointerfaces 1994, 3, 49-62... 

Stoddart and coworkers have reported chiral triethylene glycols prepared from D-mannitol (Curtis et al., 1977). Tartaric acid has been used most often to prepare a variety of chiral di-substituted ethylene glycols (Ando et al., 1978 I3ehr et al., 1980 Girodeau et al., 1975). The preparation of 1,4-di-O-benzyl-L-threitol is a good example of the use of tartaric acid (Mash et al.,... 

Trifluoroperoxyacetic acid is also an efficient reagent for oxidation of olefins to -glycols (preparation see the Section on Epoxides) 109 in this reaction the -glycols are first formed as monoesters with trifluoroacetic acid and are obtained therefrom by treatment with methanol. Excellent yields of -glycols are obtained by adding triethylammonium trifluoroacetate to the reaction mixture. 

The reaction product of adipic acid and propylene glycol prepared with a slight excess of glycol is given by the following formula ... 

The results (Table 2) show that catalytic reactivity is weakly influenced by ageing test despite the decrease of surface areas, the stabilization of which is reached after the third run. (Ethylene-glycol preparation gives the higliest specific area and activity.)... 

Phosphorus pentachloride and ethylene oxide gave ethylene dichloride, C H CP. Propylene, butylene, and amylene glycols, prepared by exactly the same general reaction as ethylene glycol, showed exactly the same chemical properties, as Wurtz (following the lead of Berthelot s publications on glycerine) showed in tedious detail. It was said also of Hofmann that the mere production appears at all times to have given him infinite pleasure. ... 

The result for glycol is quite expected. The work of Nozaki and Tanford [6] on the AGf of transfer of hydrophobic side chains from water to glycol prepares us to expect... 

Hydroxy-terminated polyethers have now assumed a dominant role in the commercial production of polyurethanes. The most widely used polyethers are derivatives of propylene oxide and these polymers are described in Section 8.4.3.1. Linear, glycol-initiated propylene oxide polymers and propylene oxide-ethylene oxide block copolymers find some use in the preparation of elastomers. Polyether triols of relatively high molecular weight (about 3000) are extensively used for the production of flexible foams whilst polyols of low molecular weight (about 500) are used for rigid foams and surface coatings. Poly(oxytetramethylene) glycols prepared from tetrahydrofuran (Section 8.4.6) are used for the preparation of elastomers and spandex fibres. 

Baeg MK, Park JM, Ko SH, Min GJ, Lee KJ, Yang JH, et al. Seizures due to hyponatremia following polyethylene glycol preparation a report of two cases. Endoscopy 2013 45(Suppl. 2 UCTN) E269-70. 

Figure 7.37 Plasma diazepam levels following intramuscular administration of diazepam O in propylene glycol vehicle x in a Cremophor EL vehicle compared with intravenous administration of the propylene glycol preparation. From Kan to [171] with permission.

Stevels W M, Bernard A, Van De Witte P, Dijkstra P J, Feijen J (1996), Block copol5Tners of poly(lactide) and poly(s-caprolactone) or poly(ethylene glycol) prepared by reactive extrusion , J. Appl. Polym. Sci., 62, 1295-1301. 

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