Methanol steam distillation

Remove most of the methanol by distillation on a steam bath, and dilute the residue with 100 ml. of water. Extract the mixture with ether, wash the upper layer with water, and dry it rapidly with a little anhydrous magnesium sulphate. Remove the ether by flash distillation, and distil the residual pale yellow oil under diminished pressure. Collect the m-nitrobenzyl alcohol at 183-185°/17 mm. it solidifies to a pale yellow solid, m.p. 30°, when cooled in ice. The yield is 13 g. 

Methyl salicylate is produced synthetically for commercial purposes by the esterification of salicylic acid with methanol or by extraction by steam distillation of wintergreen leaves or sweet birch bark. The source, natural or synthetic, is declared on the label. The methyl salicylate NF must assay not less than 98.0% and not more than 100.5% and be processed by Good Manufacturing Practice described in USP (20). 

A solution of 85.8 g (0.2 moles) of 3/ -acetoxy-27-norchoIest-5-en-25-one in 500 ml of anhydrous thiophen-free benzene is added to a Grignard solution prepared from 24.3 g (1 g-atom) of magnesium and 149 g (1.05 moles) of freshly distilled methyl iodide in 575 ml of anhydrous ether. The mixture is refluxed for 3 hr and allowed to stand overnight. After cooling to 5° the complex is decomposed by the slow addition of 200 ml of ice water and 400 ml of 50% acetic acid solution, and steam distilled until no more oil passes over. The residual product is filtered, washed with water and dried at 80°. Crystallization from methanol gives 70 g (87%) of cholest-5-ene-3)5,25-diol mp 179.5-181°. The analytical sample melts at 181.5-182.5° [a]o —39° (CHCI3). 

According to U.S. Patent 3,225,030, 1,500 grams of dried ground plant of Vinca rosea were Intimately mixed with 1,000 ml of a 2% tartaric acid solution, and the mixture was extracted with three 9-liter portions of benzene. The benzene extracts were combined and were concentrated in vacuo to about 1,500 ml. The concentrate was mixed with 1 liter of 2% tartaric acid and the mixture was steam-distilled under reduced pressure until all of the benzene had distilled over. The insoluble residue was dissolved in hot methanol, a second 1-liter portion of 2% tartaric acid solution was added, and the mixture was steam-distilled under reduced pressure until all of the methanol had distilled. 

Acetochlor and its metabolites are extracted from plant and animal materials with aqueous acetonitrile. After filtration and evaporation of the solvent, the extracted residue is hydrolyzed with base, and the hydrolysis products, EMA and HEMA (Figure 1), are steam distilled into dilute acid. The distillate is adjusted to a basic pH, and EMA and HEMA are extracted with dichloromethane. EMA and HEMA are partitioned into aqueous-methanolic HCl solution. Following separation from dichloromethane, additional methanol is added, and HEMA is converted to methylated HEMA (MEMA) over 12 h. The pH of the sample solution is adjusted to the range of the HPLC mobile phase, and EMA and MEMA are separated by reversed phase HPLC and quantitated using electrochemical detection. 

The catalyst is filtered, 200 g. (155 ml.) of 25% aqueous sodium hydroxide is added to the filtrate, and the mixture is heated under reflux for 1 hour. The condenser is replaced by a short Vigreux column and distillation head, and the heating is continued until most of the methanol has distilled. The two-phase residue is cooled and extracted with two 100-ml. portions of ether. The ether is removed on a steam bath, and the residue is distilled... 

To a stirred suspension of 1.9 g orthocarbamoyl cinnamamide in 50 ml methanol add 26 ml 0.77 N NaOCl and heat in a distillation apparatus at 40° for 2 hours, or until no more indole is distilled off (can use the indole tests described earlier). Extract the distillate with CHCI3 and dry, evaporate in vacuum (or steam distill the solvent) to get about 45% indole. 

Thus, P.Y.108 is commercially produced by heating l,9-anthrapyrimidine-2-carboxylic acid with 1-aminoanthraquinone and thionyl chloride in a high boiling solvent, such as o-dichlorobenzene or nitrobenzene, to 140 to 160°C. The product is separated, washed with methanol, and residual solvent removed by steam distillation. The aqueous suspension is then boiled down with sodium hypochlorite solution. 

The aerial parts were leached by soaking 100 g of fresh plants in 100 mL of distilled water. Soil extracts were prepared in a 2 1 proportion. The organic extracts of leaves were obtained with the following solvents hexane, ethyl acetate, chloroform, benzene, acetone, and methanol. The essential oils were obtained by steam distillation and the pure substances with several extraction techniques (11, 12, 13, 14). 

Liberation of methanol during decomposition of 1-methoxy-heptyl-l-hydroperoxide was demonstrated by holding a hot copper wire in the vapor. The odor of formaldehyde was detected. From the solution, the oxime of heptaldehyde was obtained (m.p., 54-55.5°C.) undepressed in admixture with an authentic sample. (Found C, 65.16 H, 11.55 N, 10.83%. C7Hi5ON requires C, 65.07 H, 11.70 N, 10.84%.) Another sample of the hydroperoxide (0.73 gram) was boiled for a few minutes with dilute H2S04. The solution was cooled, excess of sodium hydroxide was added, and the mixture was boiled under reflux for 1.5 hours, then acidified and steam-distilled. The ether extract of the distillate was separated into neutral and acid (0.071-gram) fractions. From the latter, the amide of heptoic acid (m.p. 92-94°C.) was obtained. 

To a flask equipped with two dropping funnels and containing 2 liters of saturated sodium chloride solution, 50.0 gm (0.51 mole) of cuprous chloride, 2.0 gm of copper powder, and 50 ml of concentrated hydrochloric acid warmed to 75°C is added a 30% sodium cyanide solution until the pH approaches approximately 3-4. At this time 150.0 gm (2.0 mole) of propargyl chloride is added dropwise over a 4-hr period. At the same time, more of the aqueous 30 % sodium cyanide is added to keep the pH constant at 3-4. The reaction product is later steam-distilled from the catalyst solution, separated from the water, dried, and fractionally distilled to afford 96.0 gm (73 %), b.p. 60°-67°C (95 mm), n ° 1.44-1.45. This product is contaminated with propargyl cyanide and is refractionated to afford pure cyanoallene, b.p. 50°-51.5°C (50 mm), d° 1.4612, Amax 46,500 cm 1, emax 14,200 (methanol). 

Preservatives in cheese may be separated after their isolation using a steam distillation (74) on an LiChrosorb RP-18 (25-cm X 4.0-mm ID) column with a mobile phase of methanol-0.02 M phosphate buffer (30 70) at pH 7.2 with 0.005 M tetrabutylammonia as the ion-pair reagent at UV 235 nm. Sorbic and dehydroacetic acids are determined by HPLC using a reverse-phase column (74). 

Equip a 500-ml three-necked flask with an efficient stirrer (e.g. a Hershberg stirrer, Fig. 2.49) and a reflux condenser stopper the third neck. Place a solution of 30 g of sodium hydroxide in 100 ml of water, and also 20.5 g (17.1 ml, 0.167 mol) of pure nitrobenzene in the flask, immerse it in a water bath maintained at 55-60 °C, and add 21 g (0.117 mol) of anhydrous glucose in small portions, with continuous stirring, during 1 hour. Then heat on a boiling water bath for 2 hours. Pour the hot mixture into a 1-litre round-bottomed flask and steam distil (Fig. 2.102) to remove aniline and nitrobenzene. When the distillate is clear (i.e. after about 1 litre has been collected), pour the residue into a beaker cooled in an ice bath. The azoxybenzene soon solidifies. Filter with suction, grind the lumps of azoxybenzene in a mortar, wash with water and dry upon filter paper or upon a porous plate. The yield of material, m.p. 35-35.5 °C, is 13 g (79%). Recrystallise from 7 ml of rectified spirit or of methanol the m.p. is raised to 36 °C. 

In the case of selective extraction of compounds from steam distillate after pH adjustment, about 1.5 L distillate were collected by co-distilling 200 g of powdered nuts with 2.5 L of water. The basic, neutral and acidic compounds were extracted using either methylene chloride or ether and the solvent was removed by distillation. In the case of the acidic fraction, the ether extract was methylated by refluxing with methanol-sulphuric acid (50 1) reagent for 2 hours. The methylated samples were washed free of acid and extracted with redistilled hexane, dried and stored frozen. 

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