Water with EtOH

PIcollnIc aldehyde (4). BenzenesuHonyl chlonde (6 92 g, 40 mmol) was added with stirring to a chilled solution ol picollnic hydrazide 2 (4 62 g, 33 mmol) in pyndlne (3S mL). After l h the solvent was removed In vacuum, the residue stirred with water, liliered and the solid washed with EtOH and EtzO to afford 10 5 g ol 3 (100%), mp 202-203°C... 

S rtMtoxy-2-pyra20llna (3). Obutyl ethyleneboronaie 1 (9 2 g, 50 mmol) and 2 (9.2 g, SO mmol) was kept at 20-30°C under N2 ttien healed on a water bath tor 12 days. Alter oooflng to -15°C the upper layer (inbutyl borate) was removed. The lower layer was washed with groin and treated with EtOH (15 mL). Distillation gave 3 16 g (44%) of 3. bp 65-70 Y. 1 mm. 

A-Acetylanthranilic acid [89-52-1] M 179.1, m 182-184 , 185-186 , 190 (dec), pK 3.61. Wash with distilled H2O and recrystallise from aqueous AcOH, dry and recrystallise again from EtOAc. Also recryst from water or EtOH. [J Chem Soc 2495 7957 J Am Chem Soc ll 6698 7955.]... 

N-Acetylglycine [543-24-8] M 117.1, m 206-208 , pKf-1.92, pKi 3.69. Treated with acid-washed charcoal and recrystd three times from water or EtOH/Et20 and dried in vacuo over KOH [King and King J Am Chem Soc 78 1089 1956],... 

Dibenzothiophene [132-65-0] M 184.3, m 99 . Purified by chromatography on alumina with pet ether, in a darkened room. Crystd from water or EtOH. 

Dissolved in a small volume of hot water and ppted with EtOH, twice. Repeated once more but with charcoal treatment of the aqueous soln, and filtered before addition of EtOH. 

Purified by azeotropic distn with EtOH, followed by washing out the EtOH with water, drying and distn [Streiff et al. J Res Nat Bur Standi 331 1946]. 

Dimethylpentane/708-08-77 M 100.2, b 80.5 , d 0.763, n 1.3814, n 1.37882. Extracted repeatedly with cone H2SO4, washed with water, dried and distd. Percolated through silica gel (previously heated in nitrogen to 350°). Purified by azeotropic distn with EtOH, followed by washing out the EtOH with water, drying and distn. 

Maltose (H2O) [6363-53-7] M 360.3, m 118 . Purified by chromatography from aqueous soln on to a charcoal/Celite (1 1) column, washed with water to remove glucose and other monosaccharides, then eluted with aqueous 75% EtOH. Crystd from water, aqueous EtOH or EtOH containing 1% nitric acid. Dried as the monohydrate at room temperature under vacuum over H2SO4 or P2O5. 

Distilled with steam and crystd from water or EtOH. 

Pinacoi (anhydrous) [76-09-5] M 118.1, m 41.1 , b 172 . The hydrate is rendered anhydrous by azeotropic distn of water with benzene. Recrystd from benzene or toluene/pet ether, absolute EtOH or dry diethyl ether. Recrystn from water gives the hexahydrate. 

Pyronin Y [3,6-bis(dimethylamino)xanthylium chloride] [92-32-0] M 302.8, m 250-260, Cl 45005, Xmax 522nm, pKesi Commercial material contained a large quantity of zinc. Purified by dissolving Ig in 50mL of hot water containing 5g NaEDTA. Cooled to 0, filtered, evapd to dryness and the residue extracted with EtOH. The soln was evaporated to 5-lOmL, filtered, and the dye pptd by addition of excess dry diethyl ether. It was centrifuged and the crystals were washed with dry ether. The procedure was repeated, then the product was dissolved in CHCI3, filtered and evapd. The dye was stored in a vacuum. 

Trichloroethane and 1,1,1,2-tetrachloroethane can be removed by counter-current extraction with EtOH/water. 

Barium tetrathionate [82203-66-5] M 361.6. Purified by dissolution in a small volume of water and ppted with EtOH below 5°. After drying the salt was stored in the dark at 0°. 

Calcium thiosulfate [10124-41-11 M 152.2, m 43-49°, pKj 0.6, pKj 1.74 (for H2S2O3). Recrystd from water below 60° in a N2 atmosphere, followed by drying with EtOH and Et20. Stored in a refrigerator. [Pethybridge and Taba J Chem Soc, Faraday Trans 7 78 1331 1982.]... 

Mercuric iodide (red) [7774-29-0] M 454.4, m 259 (yellow >130°), b 350°(subl), d 6.3. Crystd from MeOH or EtOH, and washed repeatedly with distilled water. Has also been mixed thoroughly with excess 0.00IM iodine solution, filtered, washed with cold distilled water, rinsed with EtOH and Et20, and dried in air. POISONOUS. 

Metanil Yellow (3[ 4-phenylamino phenylazo]-benzenesulfonic acid) [587-98-4] M 375.4, pKes, <0. Salted out from water three times with sodium acetate, then repeatedly extracted with EtOH [McGrew and Schneider, J Am Chem Soc 72 2547 7950]. 

Potassium iodide [7681-11-0] M 166.0, pK -8.56 (for HI). Crystd from distilled water (0.5mL/g) by filtering the near-boiling soln and cooling. To minimise oxidation to iodine, the crystn can be carried out under N2 and the salt is dried under vacuum over P2O5 at 70-100°. Before drying, the crystals can be washed with EtOH or with acetone followed by pet ether. Has also been recrystallised from water/ethanol. After 2 recrystns ACS/USP grade had Li and Sb at <0.02 and <0.01 ppm resp. 

Sodium polyacrylate (NaPAA) [9003-04-7]. Commercial polyacrylamide was neutralised with an aqueous solution of NaOH and the polymer ppted with acetone. The ppte was redissolved in a small amount of water and freeze-dried. The polymer was repeatedly washed with EtOH and water to remove traces of low... 

Sodium p-toluenesulfonate [657-84-1] M 194.2, pK -1.34 (for -SOs"). Dissolved in distilled water, filtered to remove insoluble impurities and evaporated to dryness. Then crystd from MeOH or EtOH, and dried at 110°. Its solubility in EtOH is not high (maximum 2.5%) so that Soxhlet extraction with EtOH may be preferable. Sodium p-toluenesulfonate has also been crystd from Et20 and dried under vacuum at 50°. 

Titanyl sulfate (Ti0S04.2H20) [13825-74-6] M 160.0. Dissolved in water, filtered and crystd three times from boiling 45% H2SO4, washing with EtOH to remove excess acid, then with Et20. Air dried for several hours, then oven dried at 105-110°. [Hixson and Fredrickson Ind Eng Chem 37 678 7945.]... 

Recrystd from 60% aq EtOH, then twice from water, and dried for 12hours in a vacuum at 80°. Also purified by pptn from water with 1,1,2-trichloroethylene. The ppte was isolated, washed and resuspended in water. This was boiled to steam distil the trichloroethylene. The soln was freeze-dried to recover the cyclodextrin. [Armstrong et al. J Am Chem Soc 108 1418 1986],... 

Pectin [9000-69-5] Mr 25,000-100,000, amorphous. Dissolved in hot water to give a 1% soln, then cooled, and made about 0.05M in HCl by addition of cone HCl, and ppted by pouring slowly, with vigorous stirring into two volumes of 95% EtOH. After standing for several hours, the pectin is filtered onto nylon cloth, then redispersed in 95% EtOH and stood overnight. The ppte is filtered off, washed with EtOH/ElaO, then Et20 and air dried. 

General Conditions for each step and selectivity of m-substituted anilines As previously mentioned, Hauser and Reynolds reported on factors governing the first step of the Conrad-Limpach reaction but they tvere by no means exhaustive. Other than the conditions reported above for the first step, HClAleOH, CHCI3 or CHCI2 (neat or with acid catalyst), PhMe or PhH with removal of water with or without acid catalyst, or EtOH/AcOH/CaS04 were reported to provide the desired enamino-ester from an aryl amine and 3-keto-ester. Hauser and Reynolds also noted that o-nitroaniline and o-nitro-p-methoxyaniline failed to form the desired enamino-ester under conditions which they reported. 

Carboxyl redution. A sample of pennethylated PI (5 mg) was carboxyl-reduced by a modification of the method described by Lindberg and Lbnngren [9], as follows. The methylated fraction was solubilized and added a mixture of LiAlH4 (25 mg) in THF (5 mL) at 20 °C for 4 h. and refluxed during 1 h. The excess of reagent was destroyed with ethyl acetate (5-6 drops) and water (10 drops) and the pH of the mixture adjusted to neutrality with acetic acid. The insoluble residue was removed by centrifugation. The reduced fi action was precipitated with EtOH. The reaction was monitored by l.r. specroscopy. Hydrolysis products were analysed by GC-MS as methyl alditol acetates... 

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