Pentane acetal from

The crude prostaglandin extract was purified and fractionated by TLC on silicagel F, using the organic phase of ethyl acetate - 2,2,4-trimethyl pentane-acetic acid - water (11 0 50 20 100) in a non-equilibrated tank and applying the double development technique as described by Sun et al.(7) Under the conditions used, 6-oxo PGF elutes as a sharp zone and is well resolved from coloured haem zone, which was always... 

The p-hydroxybenzoate esters can be separated with pentane-acetic acid (88 -f 12) on silica gel layers containing a fluorescence indicator [32]. These compounds are then detected in short wave UV radiations as dark spots of fluorescence quenching (Fig. 179). The layers are prepared from silica gel 6 by adding 2 % of the fluorescent material Leuchtstoff ZS-Super (Firm 118) or by using a silica gel, such as silica gel GF254 (Firm 88), which already contains a fluorescent additive. 

Solvents Toluene-n-pentane-acetic acid (6 3 2) and acetic acid-water (1 3) for first and second dimension, respectively. Alkaline treatment Spray O.OS M NaOH in methanol-water (1 1), heating at ISO C for 30 min, UV. Source From Ref. 103. 

Hydroxyacetanilide. This derivative (21), also known as 4-acetamidophenol, acetaminophen, or paracetamol, forms large white monoclinic prisms from water. The compound is odorless and has a bitter taste. 4-Hydroxyacetani1 ide is insoluble in petroleum ether, pentane, and ben2ene slightly soluble in diethyl ether and cold water and soluble in hot water, alcohols, dimethylformamide, 1,2-dichloroethane, acetone, and ethyl acetate. The dissociation constant, pfC, is 9.5 (25°C). 

Phenyl acetate [122-79-2] M 136.2, b 78°/10mm, d 1.079, n 1.5039. Freed from phenol and acetic acid by washing (either directly or as a soln in pentane) with aqueous 5% Na2C03, then with saturated aqueous CaCl2, drying with CaS04 or Na2S04, and fractional distn at reduced pressure. 

Treatment with acetic anhydride and pyridine at room temperature followed by recrystallization of the crude product from chloroform-pentane gives the 3-acetate of (83a) mp 277-279° [aj —101° (dioxane). 

The reaction is a sensitive one, but is subject to a number of interferences. The solution must be free from large amounts of lead, thallium (I), copper, tin, arsenic, antimony, gold, silver, platinum, and palladium, and from elements in sufficient quantity to colour the solution, e.g. nickel. Metals giving insoluble iodides must be absent, or present in amounts not yielding a precipitate. Substances which liberate iodine from potassium iodide interfere, for example iron(III) the latter should be reduced with sulphurous acid and the excess of gas boiled off, or by a 30 per cent solution of hypophosphorous acid. Chloride ion reduces the intensity of the bismuth colour. Separation of bismuth from copper can be effected by extraction of the bismuth as dithizonate by treatment in ammoniacal potassium cyanide solution with a 0.1 per cent solution of dithizone in chloroform if lead is present, shaking of the chloroform solution of lead and bismuth dithizonates with a buffer solution of pH 3.4 results in the lead alone passing into the aqueous phase. The bismuth complex is soluble in a pentan-l-ol-ethyl acetate mixture, and this fact can be utilised for the determination in the presence of coloured ions, such as nickel, cobalt, chromium, and uranium. 

Due to its commercial importance, the synthesis of copper phthalocyanine (PcCu) is the best investigated of all the phthalocyanines. Copper phthalocyanine is prepared from phthalonitrile and copper(I) chloride without solvent137 and also in a melt of urea.229,277 Additionally, the insertion of copper into metal-free phthalocyanine in butan-l-ol and pentan-l-ol is possible. The copper salts used in this case are copper(I) chloride112 and copper(II) acetate.290 Starting from copper(II) acetate, copper phthalocyanine can also be prepared in ethylene glycol.127 As mentioned above, copper phthalocyanine often occurs as a byproduct of the Rosenmund-von Braun reaction. To increase the yield of the phthalocyanine the solvent dimethylformamide can be substituted by quinoline. Due to the higher boiling point of quinoline, the copper phthalocyanine is the main product of the reaction of copper(I) cyanide and 1,2-dibromoben-zene.130... 

With Aromatic Aldehydes. To a solution of 10.3 g (20 mmol) of 2,3,4,6-tetra O-pivaloyl-/ -i>galactopyra-nosylaminc in 50 rnL of /-PrOI 1 or heptane are added 30 mmol of the corresponding aromatic aldehyde and 30 drops of acetic acid. After 30 min to 2 h, the Schiff base precipitates from the /-PrOH solution. When the reaction is carried out in heptane, 2 g of Na2S04 or 3 g of 3 A molecular sieves are added after 15 min, and the mixture is filtered. On cooling to 0 °C the Schiff base crystallizes from the heptane solution. The aldimines are collected by filtration and rapidly washed with ice-cold /-PrOH or pentane, respectively. Generally, they are pure enough for further transformations. 

The addition of the anion of ( + )-rm-butyl [(/J)-4-methylphenylsulfinyl]acetate to a,/ -unsatitrated esters gave 2,3-disubstituted 1-tm-butyl 5-ethyl 2-[(/ )-4-methylphenylsulfinyl]pentane-dioates which were converted to -substituted -lactones. The enantiomeric purities of the latter ranged from 0-24 %23. 

Vicinal iodo carboxylates may also be prepared from the reaction of olefins either with iodine and potassium iodate in acetic acid/ or with N-iodosuccinimide and a carboxylic acid in chloroform. " A number of new procedures for effecting the hydroxylation or acyloxylation of olefins in a manner similar to the Prevost or Woodward-Prevost reactions include the following iodo acetoxylation with iodine and potassium chlorate in acetic acid followed by acetolysis with potassium acetate reaction with iV-bromoacetamide and silver acetate in acetic acid reaction with thallium(III) acetate in acetic acid and reaction with iodine tris(trifluoroacetate) in pentane. ... 

Formation of mixtures of products in these reactions can be attributed largely to the properties of the acetate group. The reactions of a number of cycloalkenes with thallium(III) salts have been investigated in some detail and the results obtained have served both to elucidate the stereochemistry of oxythallation and to underline the important role assumed by the anion of the metal salt in these oxidations. The most unambiguous evidence as to the stereochemistry of oxythallation comes from studies by Winstein on the oxythallation of norbornene (VII) and norbornadiene (VIII) with thal-lium(III) acetate in chloroform, in which the adducts (IX) and (X) could be precipitated from the reaction mixture by addition of pentane 128) (Scheme 11). Both by chemical means and by analogy with the oxymercuration... 

The alkenyl oxonium ion dienophiles generated from dioxolanes can be made diastereoselective by use of chiral diols. For example, acetals derived from anti-pentane-2,4-diol react under the influence of TiCl4/Ti(/-OPr)4 with stereoselectivity ranging from 3 1 to 15 1. 

Figure 10 Capillary ion analysis of 30 anions 1 = thiosulfate, 2 = bromide, 3 = chloride, 4 = sulfate, 5 = nitrite, 6 = nitrate, 7 = molybdate, 8 = azide, 9 = tungstate, 10 = monofluorophosphate, 11 = chlorate, 12 = citrate, 13 = fluoride, 14 = formate, 15 = phosphate, 16 = phosphite, 17 = chlorite, 18 = galactarate, 19 = carbonate, 20 = acetate, 21 = ethanesulphonate, 22 = propionate, 23 = propanesulphonate, 24 = butyrate, 25 = butanesulphonate, 26 = valerate, 27 = benzoate, 28 = D-glutamate, 29 = pentane-sulphonate and 30 = D-gluconate. Experimental conditions fused silica capillary, 60 cm (Ld 52 cm) x 50 p i.d., voltage 30 kV, indirect UV detection at 254 nm, 5 mM chromate, 0.5 mM NICE-Pak OFM Anion-BT, adjusted to pH 8.0, with 100 mM NaOH. (From Jones, W. R. and Jandik, R, /. Chromatogr., 546, 445,1991. With permission.)...

Many analytical techniques are in use for the qualitative and quantitative evaluation of monomers and oligomers extracted from PA6 (GC, differential refrac-tometry, IR, PC, SEC, HPLC, RPLC, etc.). FTIR has been used for quantitative analysis of caprolactam oligomer content (extract %) in polyamide-6 [113], The method, which involves a 3h extraction in boiling methanol, is suitable for process control and plant environment. Kolnaar [114] has used FTIR characterisation of fractional extracts with pentane, hexane, and heptane of HDPE for blow moulding applications. Vinyl acetate in packaging film has similarly been determined by quantitative FUR. 

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