Three alkaline treatments

Lopez-Abelairas and co-workers [30] proposed and compared a few recovery methods, namely sulfuric acid with bleaching steps, and NaClO, NaOH and NaOH with a halogenated solvent (one acid treatment and three alkaline treatments). It was found that the PHA extracted from the acid treatment exhibited the highest purity (98%) and lowest polymer degradation. In addition, this extraction method gave the lowest recovery cost it was therefore concluded to be the best choice for PHA recovery in this study. 

Benzo>l,2-thiazines.—Syntheses of new 1,2-benzothiazines of pharmacological interest continue to attract most of the attention in this area. Sianesi et aL now report some convenient procedures for preparing the three isomeric dihydrobenzothiazine dioxides (9)—(11) and their N-substi-tution products. For instance, (10) is obtained in 54% yield by dehydration of o-(2-aminoethyl)benzenesulphonic acid with POCI3, and also by hydrogenation in acidic medium of the corresponding cyanosulphonamide (77% yield) or by alkaline treatment of o-(2-chloroethyl)benzenesulphonamide (83% yield). Several 3,4-dihydro-l/f-2,3-benzothiazin-4-one 2,2-dioxides and 3,4-dihydro-177-l,2-benzothiazin-4-one 2,2-dioxides, as well as 3,4-... 

Three amino-sugar syntheses have employed 2,3-0 -isopropylidene-D-glyceraldehyde (37) as a starting material. The 2-amino-2-deoxy-D-rlbose derivative (38) was obtained via a stereoselective aldol condensation using an ethoxyacetylene-derived enolate (39) alkaline treatment of the derived a-chloro-8-hydroxy-esters (40) gave a 4 1 mixture of trans-substltuted epoxides from which the predominant Isomer (41) was isolated chromatographically, aminated, and reduced... 

The mixture of galactans from cystocarpic samples of I. undulosa (Cc) were fractionated (Table 2) and treated as depicted in Fig. 4 (Flores, Cerezo, Stortz 2002). Bulk precipitation of Cc with 2M KCl yielded 62 % of an insoluble product (Cl, K/r-carrageenans) and 31% of a soluble one (Cs, p/v-carrageenans). Alkaline treatment of Cl and Cs proceeded with excellent yields (93-95%), giving CIT and CsT in which the precursor units (4-linked a-galactose 6-sulfate and 2,6-disulfate) were cycllzed. Both products were fractionated by precipitation with increasing concentrations of potassium chloride, yielding three fractions insoluble at O.IM, IM, and 2M KCl and one soluble at the latter concentration (Table 3). 

On hydrogenation at 80°, or on electrolytic reduction, aphyllidine is converted into d-sparteine (p. 133). On exhaustive methylation one nitrogen atom is eliminated in three stages, leaving a product, b.p. 235-255°/ll mm., as a viscous, yellow, alkaline oil of uncertain composition. Aphylline, on similar treatment, yields hemiaphylline, CjgH jON, b.p. 217-220°, as a viscous, yellow oil, not markedly basic. 

The soil was collected from the Mezquital Valley, located near Pachuca in the State of Hidalgo (Mexico). The irrigation water used was slightly alkaline with a pH of 8.4. The experiment was carried out under greenhouse conditions. Soil collected from three sub sites was placed into cylindrical pots. Five treatments were established in order to study the effect of wastewater and urea on the cultivation of maize (Zen mays L.). The treatments were a) SMWW, maize plant plus wastewater b) SMUREA, maize plant plus urea as fertilizer c) SUREA, uncultivated soil and urea as fertilizer d) SWW, uncultivated soil plus wastewater and e) SCONTROL treatment, soil plus tap water. Soils from the SMWW and SWW treatments were irrigated with 1000 mL of wastewater every 7 days from the first day onwards, making a total of 13 times overall. This means that a total amount of mineral N equivalent to 120 kg N ha-1 was added to each maize plant, i.e. the recommended amount of N fertilizer for maize. 

A preformed chitosan-silica composite with 60% weight inorganic part [7] is used as the source of silica for the zeolite synthesis. An alkaline solution of sodium aluminate (Na 2.1 M, Al 1 M) was used in three methods of preparation (A) beads of the chitosan-silica composite were stirred overnight in the aluminate solution, extracted and submitted to a hydrothermal treatment at 80 °C during 48h (B) beads of the chitosan-silica composite were immersed in the aluminate solution and the system underwent a hydrothermal treatment at 80 °C for 48h (C) beads of the chitosan-silica composite were stirred overnight in the aluminate solution, extracted, dried at 80 °C and exposed to water vapour at 80°C during 48h. 

Treatment of the optically active gem-borazirconocene alkanes with deuterium oxide followed by alkaline oxidation affords the corresponding optically active 1-deuterio primary alcohols. The enantiomeric excess of the resulting primary alcohols represents the diaster-eoselectivity of the asymmetric hydrozirconation (Scheme 7.13). Based on the cost and availability of optically active ligands, three types were explored monoterpenes, 1,2-diols, and 1,2-amino alcohols. Hydrozirconation of optically pure 1-alkenyl boranes 39 provided optically active 1,1-bimetallics 40. 

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