NaOH extractions

Phenethylanillne 1 (hydrochloride) (23 3 g 01 mol) was heated in a sealed tube at 200 230 Clor6h The cooled mixture was extracted with 15% HCI and Et20 The Et20 layer was extracted with HCI The acid extract alter neutralization with S% NaOH, extraction with PhH and distillation gave 2 3 g of aniline and 4 2 g of 2 and 3 (24%), bp 165 170°C m a ratio of 3 7... 

M NaOH. Extracted into diethyl ether. Sublimed in vacuo. 

Dissolved in 20% NaOH, extracted with a small amount of C6H6, then steam distd, until clear. The soln was then cooled and acidified slightly with 15% H2SO4. The thiol was distd out, dried with CaS04 or CaCl2, and fractionally distd under N2 [Mathias and Filho J Phys Chem 62 1427 1958]. Also purified by pptn as lead mercaptide from alcoholic soln, with regeneration by adding dilute HCl to the residue after steam distn. All operations should be carried out in a fume cupboard due to the TOXICITY and obnoxious odour of the thiol. 

Dissolved in aqueous 20% NaOH, extracted with a small amount of benzene and then steam distd until clear. After cooling, the alkaline soln was acidified slightly with 15% H2SO4 and the thiol was distd off, dried with CaS04, CaCl2 or 4A molecular sieves, and fractionally distd under nitrogen [Ellis and Reid J Am Chem Soc 54 1674 1932]. 

The solvents were evaporated in vacuo, and the residue was taken up in 80 ml of 3M hydrochloric acid. After addition of 220 ml of water, the insoluble material was filtered off, washed with 100 ml of water and then dried. The insoluble material weighed 9.5 g and was mainly unreacted bromo compound. The filtrate was reacted with 50 ml of 7 M NaOH, extracted three times with methylene chloride (50 m -t 2 x 25 ml portions), dried over potassium carbonate, and then evaporated. The yield of residue was 26.8 g which corresponds to 71.4% of the theoretical yield. This residue was a colorless solidifying oil and was dissolved in 200 ml chloroform. Hydrogen chloride was bubbled in until a sample of the solution tested acidic to wet pH indicator paper. A precipitate was obtained and recovered by filtration. The precipitate was washed with chloroform and dried. The melting point was determined to be from 246 Cto247.5°C. 

Method A 7-Chloro-5-pheny 1-177-1,4-benzodiazepine-2(3//)-thionc (28.7 g. O.lOmol) and piperidine (17.0 g, 0.20 mol) in a mixture of MeOH (250 mL) and DMSO (50 mL) were heated under reflux until no more H2S was evolved (1.5 h). The mixture was evaporated in vacuo and the residue was dissolved in dil HC1. The solution was washed with Et20 and then made alkaline with aq NaOH. Extraction with CH2C12, followed by drying and evaporation, gave the product yield 20.25 g (60%) mp 115 116 C (aq F.tOH). 

Urine Acidify and heat to hydrolyze add NaOH extract with anhydrous ethyl ether derivatize with diazoethane concentrate add hexane concentrate and cleanup on silica gel elute with benzene-hexane (PNP) GC/ECD 20 pg/L (20 ppb) 85-98 Shafiketal. 1973b... 

TMSOTf 20 (0.11 g, 0.5 mmol) is added to a solution of a-phenyl-N-methylni-trone 976a (0.68 g, 5.0 mmol) and allyltrimethylsilane 82 (0.69 g, 6 mmol) in dry CH2CI2 (5 mL). After 36 h at room temperature the reaction mixture is quenched with 3 M aqueous HCl and stirred for 1 h. After neutralization with 3 M NaOH, extraction with Et20 (2x25 mL), and evaporation the residue is purified by flash chromatography on silica gel with hexane-ethyl acetate (7 3) to give 0.763 g (86%) 978a as a crystaUine solid, m.p. 93-95°C [70] (Scheme 7.59). 

NaOH in ihe presence of NaBH4 for 6 h at room temperature. The alkaline extraction was repeated twice and the supernatant combined the NaOH extract acidified to pH 5 with 50 % acetic acid, exhaustively dialyzed, polysaccharide precipitated with EtOH (2 vol.) and washed with EtOH and Me2CO. 

Woolson et al. (1971) used a modified soil P procedure to study distribution of As in U.S. soils. The mass of the residual As in both uncontaminated and soils contaminated with arsenic pesticides from Washington and Oregon is found as the Fe oxide bound As (0.1 N NaOH extractable), followed by the Al oxide and the Ca bound As (extracted by NH4F and H2S04, respectively). 

To 13 g 3,4-dimethoxyphenol in 20 ml methanol add a solution of 5.3 g KOH in 100 ml methanol and then 12 g methyl iodide. Reflux two hours, add 300 ml water and make pH 10 with 5% NaOH. Extract with ether and dry, evaporate in vacuum the pooled extracts to get a clear oil. Mix 17.3 g N-methyl-formanilide and 19.6 g POCI3 and let stand at room temperature for one-half hour. Add 8.5 g of the oil, heat two hours on steam bath (or boiling water) and pour... 

Dissolve 3.3 g 4,5, or 6 methoxy (or ethoxy, methyl, etc.)-tryptamine or its HC1 salt in 350 ml 0.1 N HC1 heat on steam bath two hours with 1.1 g glycoaldehyde (reaction over when aliquot no longer gives a precipitate with dinitrophenylhydrazine). Filter, concentrate by heating on water bath or evaporate in vacuum basify with 20% NaOH and extract with ether (best to do in an extractor for eighteen hours). Dry and evaporate in vacuum the extract to get about 5 g residue or oil which may precipitate on standing. Add 250 ml 90% phosphoric acid and heat on steam bath two hours. Evaporate in vacuum (or dilute with water, basify with 20% NaOH extract with ether in extractor and dry, evaporate in vacuum the... 

Occupational air (NIOSH Method 7904) Filtered air collected in midget impinger containing NaOH extraction of filter with NaOH sulfide removed. Specific ion electrode (HCN cyanide salts) 2.5 pg CNa 96.7 at 5-21 mg/m3 NIOSH 1989a... 

Digestion with NaOH, extraction with benzene, extraction with dilute H2SO4, water removal and volume reduction GPC cleanup. 

Fish tissue Digestion with NaOH, extraction with benzene, extraction with dilute H2SO4, water removal and volume reduction GPC cleanup. GC/HCD (N mode) <20 ppb 65 (20% RSD) Diachenko 1979... 

Dimethoxy 4-ethoxybenzene. To a solution of 4-ethoxy-3-methoxyphenol (14 g) in 20 ml of MeOH is added a solution of 5.3 g of KOH in MeOH (100 ml), followed by 11.9 g of Mel. The mixture is then refluxed for two hours, then quenched with 3 volumes of H2O, and made strongly basic with 5% NaOH. Extract with ether and evaporate the pooled extracts to get the title ether as a clear oil. Yield 9.7 g. 

Adjust the urine to pH 7 with 0.1 M HC1 or 0.1 M NaOH. Extract 3 times with 2 mL of benzene, centrifuging between each extraction. 

CHEMISTRY To a solution of 5.0 g of 5-methylthiotryptamine as the free base (the hydrochloride, with mp 252-254 °C or 263-265 °C, is dissolved in H20, made basic with aqueous NaOH, extracted with CH2CI2, and the solvent removed under vacuum) in 250 mL MeOH, there was added 4.0 g NaHC03 and 6.8 g Mel. This was held at reflux for 72 h, with the addition of 1.5 g more Mel at both the 24 and the 48 h time. Removal of the volatiles under vacuum produced a white residue which was dissolved in 300 mL boiling , insolubles removed by filtration of the hot solution, and the filtrate allowed to cool. Fine white crystals appeared which were removed by filtration, and air-dried to... 

Benzamidine [618-39-3] M 120.2, m 64-66°. Liberated from chloride by treatment with 5M NaOH. Extracted into ethyl ether. Sublimed in vacuo. 

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