Methylene chloride reflux

To perform a dialytic extraction, the apparatus is assembled and preextracted for 48 hours using pyridine and methylene chloride outside and inside the membrane, respectively. The coal ftvlOO g) is then slurried in a 2-3 fold excess of pyridine (ACS reagent grade) and placed in the sample compartment, where it is constantly stirred. The methylene chloride reflux is begun at this point, and the extract collects in the receiver. When the buildup of pyridine in the receiver results in stoppage of the reflux cycle, the contents of the receiver are collected, and it is refilled with clean methylene chloride. The overflow from the sample compartment was evaporated under a flow of dry nitrogen, redissolved in pyridine, and replaced in the sample compartment daily. The dialytic extraction is slower than the soxhlet procedure, and the yield is substantially less. For example, the yield of a four day dialytic extraction of Powhatan Coal was 6%, while a two day pyridine soxhlet on the same coal yields 12-15% extract. 

A soln. of 4-amino-4 -chlorodiphenylmethane, methyl acetoacetate, and one drop of 5%-HOI in methylene chloride refluxed until no more water is collected in a water separator —y methyl / -(4-p-chlorobenzyl-anilino)-crotonate. Y 97%.—The methyl esters give better yields than the ethyl esters, both in the above condensation, and in a following ring closure to quinolines (cf. 5, 614). (F. e. s. C. E. Kaslow and R. D. Stayner, Am. Soc. 70, 3350 (1948).) s. a. 4, 750... 

The ability of several methods to extract polycyclic aromatic hydrocarbons (PAHs) and other petroleum hydrocarbons from marine sediments was examined. Comparisons of soxh-let and methylene chloride reflux methods gave extraction efficiencies that showed no statistical difference in the return of PAHs however, the return when using ball-mill tumbling was significantly lower. The relative content of individual parent PAH compounds, parent compound distributions (PCDs), and alkyl homologue distributions (AHDs) of PAHs was calculated using capillary column GC-MS. The similarities of the distributions showed that any of the three methods could have been used to calculate these distributions. An examination of several extraction methods commonly used for the extraction of petroleum hydrocarbon material from sediment samples showed differences in results that depended on the extraction method employed. In addition, the methods varied in their ability to extract resolved versus unresolved material and to return aliphatic and aromatic hydrocarbon compounds. 

Figure 5. Recovery [log (ppm dry weight)] of nonalkylated PAH compounds for methylene chloride reflux, soxhlet, and ball-mill tumbler extraction methods...

Figure 6. Comparison of PAH PCDs for replicate extractions by methylene chloride reflux, soxhlet, ana ball-mill tumbler methods...

Startg. m. prepared from 2-benzoyl-l,2-dihydroisoquinaldo-l-nitrile and 48%-HBF4 in glacial acetic acid according to Am. Soc. 93, 4479 (1971) (Y 90%) mixed with ethyl acrylate and methylene chloride, refluxed with slow addition... 

A soln. of cholesterol, tetra-O-benzyl-a-D-glucosyl chloride, and tetramethylurea in methylene chloride refluxed for 2 h through a column containing 4A molecular sieves, solvent removed, and the residue heated to 120° for 4 h product. Y 92% (a P 60 40). When the reaction was carried out at 120° for 2 h without preliminary removal of water, the yield was reduced (79%) but the a-selectivity increased to 85 15. The method is simple (applicable to both prim, and sec. alcohols) and does not require a hazardous metal. F.e. and reaction in the absence of TMU s. M. Nishizawa et al., Chem. Pharm. Bull. 37, 565-7 (1989) from 2 -unprotected glycosyl chlorides s. Tetrahedron Letters 29, 4597-8 (1988). 

A soln. of N-bromo-4-methyl-2-azetidinone in methylene chloride added with stirring and UV-irradiation by a high-pressure Hg-lamp during 5-10 min. to a refluxing mixture of allyl chloride (or another olefin such as 4-methyl-l-pentene or isoprene) and methylene chloride, refluxing with irradiation continued 0.5-1 hr. / -bromoisopropyl isocyanate. Y 93%. F. e. and procedures s. K. D. Kampe, A. 752, 142 (1971). 

A soln. of D-(-)-2-methoxy-2,4,5-trimethyl-l,3-dioxolane and trityl chloride in methylene chloride refluxed 1-2 hrs. h-(+)-erythro product. Y 90%. - The reaction occurs with inversion. - These reactions are highly regio- and stereospecific. F. e. s. M. S. Newman and C. H. Chen, Am. Soc. 95, 278 (1973). 

Chlorosulfonyl isocyanate added to a soln. of 17,18-bis(methoxycarbonyl)-6,14-ethenocodeine methyl ether in methylene chloride, refluxed 5 hrs., and the methanolic soln. of the crude product treated with excess diazomethane to methylate a small amount of demethylated material -> 1-chloro deriv. Y 81%. R. Giger, R. Rubinstein, and D. Ginsburg, Tetrahedron 29, 2393 (1973). 

A soln. of N-fluorosulfonyliminophosphoric trichloride in methylene chloride ice-cooled, stirred and treated dropwise with a mixture of methanol and methylene chloride, refluxed 1 hr. to complete HCl-elimination, ether added, and refluxed 20 min. N-fluorosulfonyl-N-methylaminophosphoryl dichloride. Y 90%. F. e. s. H. W. Roesky and W. Grosse Bowing, Ang. Ch. 83, 365 (1971). 

A mixture of equimolar amounts of homophthalic acid anhydride, veratriylidene-methylamine, and methylene chloride refluxed 10 min., and the resulting soln. allowed to stand 1 hr. at room temp. -> ( )-rran -4-carboxy-3-(3,4-dimethyoxy-phenyl)-2-methyl-3,4-dihydro-l(2H)-isoquinoline. Y 96%. F. e. s. M. A. Haimova et al.. Tetrahedron 33, 331 (1977) N-condensed N-heterocyclics s. M. Cushman, J. Gentry, and F. W. Dekow, J. Org. Chem. 42, 1111 (1977). 

A soln. of the startg. m., aq. 40%-methylamine, methanol, and methylene chloride refluxed 2 hrs. l,3-dihydro-2H-azepin-2-one deriv. (Y 87%) after reaction with K-hexacyanoferrate(III) under Ng annelated product (Y 57%). F. e. s. H.-D. Becker and K. Gustafsson, Tetrah. Let. 1976, 1705. 

A soln. of l,3-dihydro-3,7-dimethyl-2H-azepin-2-one and N-chlorosuccinimide in methylene chloride refluxed 24 hrs. 6-chloro-l,3-dihydro-3,7-dimethyl-2H-azepin-2-one. Y 97%. - Ghlorination in these cyclic dienamides occurs at G4 or Gg depending on the substitution at N, Gg, or G7, and according to the principle of least motion. F. e. s. L. A. Paquette and W. G. Farley, J. Org. Ghem. 52,2725 (1967). 

Place a mixture of 1 0 g. of the hydrocarbon, 10 ml. of dry methylene chloride or ethylene dichloride or syw.-tetrachloroethane, 2 5 g. of powdered anhydrous aluminium chloride and 1-2 g. of pure phthalic anhydride in a 50 ml. round-bottomed flask fitted with a short reflux condenser. Heat on a water bath for 30 minutes (or until no more hydrogen chloride fumes are evolved), and then cool in ice. Add 10 ml. of concentrated hydrochloric acid cautiously and shake the flask gently for 5 min utes. Filter oflf the solid at the pump and wash it with 10-15 ml. of cold water. Boil the resulting crude aroylbenzoic acid with 10 ml. of 2 -5N sodium carbonate solution and 0 2 g. of decolourising carbon for 5 minutes, and filter the hot solution. Cool, add about 10 g. of crushed ice and acidify... 

The checkers carried out this recrystallization by dissolving triphenylene in a minimum of methylene chloride maintained at reflux. Pentane was slowly added to this solution up to 90% recovery was achieved. 

A reagent which is primarily of interest as a means of converting alcohols into fluorides has been used to dehydrate C-11 alcohols in high yields. 1 la-Alcohols dehydrate rapidly with 2-chloro-l-diethylamino-l,l,2-trifluoro-ethane reagent at low temperature, while 11 j5-alcohols require refluxing methylene chloride. Traces of fluoro compounds have been detected in the products. 

Ji-Methoxy-ll, 11-ethylenedioxy-lS-methylestra-1,3,5(lO)-tnene. A solution of (+)3-methoxy-18-methylestra-l,3,5(10)-trien-17-one (5 g) dissolved in ethylene glycol (5 ml) and ethyl orthoformate (10 ml) containing />-toluenesulfonic acid (0.3 g) is heated under reflux for 2 hr in a nitrogen atmosphere. The resulting solution is diluted with methylene chloride and washed with dilute sodium bicarbonate and water. The organic phase is dried over sodium sulfate and evaporated to dryness in the presence of a trace of pyridine. Trituration of the residue with petroleum ether yields 4.7 g (82 %) of the pure ketal. 

Chloro-1 -methyl-5-phenyl-s-trizolo[4,3-a]quinoline A stirred mixture of 6triethyl-orthoacetate (0.925 g,0.0057 mol) and xylene (100 ml) was refluxed, under nitrogen, for 2 hours 40 minutes. During this period the ethanol formed in the reaction was removed by distillation through a short,glass helix-packed column. The mixture was concentrated to dryness In vacuo and the residue was crystallized from methanol-ethyl acetate to give 1.28 g of 7-chloro-1-methyl-5-phenyl-s-triazolo[4,3-a]-quinoline (83.9% yield). The analytical sample was crystallized from methylene chloride methanol and had a melting point 252.5°-253.5°C. 

A solution of 3.5 g 4-(2,3-epoxypropoxy)carbazole in 50 ml absolute alcohol is mixed with 30 ml isopropylamine and heated for 3 hours under reflux. When the reaction is finished, the reaction mixture is evaporated to dryness. The residue obtained is taken up in methylene chloride and chromatographed over an aluminum oxide column (300 g basic aluminum oxide, activity stage IV eluent methylene chloride). The eluted fractions are evaporated and the residue is dissolved in methanol and acidified with 2N ethereal hydrochloric acid. 

A mixture of 20 g of 1. [p.((3.diethylaminoethoxy)phenyl]-1,2-diphenylethanol in 200 cc of ethanol containing an excess of hydrogen chloride was refluxed 3 hours. The solvent and excess hydrogen chloride were removed under vacuum, and the residue was dissolved in a mixture of ethyl acetate and methylene chloride. 1-[p-((3.diethylaminoethoxv)phenyl] -1,2-diphenylethylene hydrochloride was obtained, melting at 148° to 157°C. This hydrochloride salt was treated with N-chlorosuccinimide in dry chloroform under reflux. The product then obtained was converted to the free base and treated with citric acid. The dihydrogen citrate salt of 1-[p-((3-diethylaminoethoxy)phenyl]-1,2-diphenylchloroethylene was obtained, melting at 116.5° to 118°C. 

A mixture of 3 grams (0.01 mol) of 7-chloro-1-methyl-5-phenyl-3H-1,4-benzodiazepin-2(1 H)-one 4-oxide, 30 ml of chloroform and 1 ml of phosphorus trichloride was refluxed for one hour. The reaction mixture was then poured on ice and stirred with an excess of 40% sodium hydroxide solution. The chloroform was then separated, dried with sodium sulfate, filtered and concentrated in vacuo. The residue was dissolved in methylene chloride and crystallized by the addition of petroleum ether. The product, 7-chloro-Tmethyl-5-phenyl-3H-1,4-benzodiazepin-2(1 H)-one, was recrystallized from a mixture of acetone and petroleum ether forming colorless plates melting at 125°-126°C. 

To a solution of 6.78 g of 6a-fluoro-9a-bromo-11 (3,17a,21-trihydroxy-16a-methyl-1,4-preg-nadiene-3,20-dione-21 -acetate in 175 ml of acetone was added 6.78 g of potassium acetate and the resulting suspension was heated under reflux for a period of 17 hours. The mixture was then concentrated to approximately 60 ml volume at reduced pressure on the steam bath, diluted with water and extracted with methylene chloride. The methylene chloride extracts were combined, washed with water, dried over anhydrous sodium sulfate and evaporated. 

The above crude bromohydrin was mixed with 2.5 grams of potassium acetate and 60 cc of acetone and refluxed for 6 hours, at the end of which the acetone was distilled, water was added to the residue and the product was extracted with methylene chloride. The extract was washed with water, dried over anhydrous sodium sulfate and the solvent was evaporated. Recrystallization of the residue from methanol furnished 800 mg of the 16,21-diacetate of 6o-fluoro-9(3,11(3-oxido-A -pregnene-16o,l7a,2l-triol-3,20-dione with MP 120° to 124°C by chromatography of the mother liquors on silica gel there was obtained 180 milligrams more of the same compound with MP 117° to 119°C. The analytical sample was obtained by recrystallization from methanol it showed MP 125° to 127°C. 

Isopropyl-4(or 5-nitroimidazole) (31 g = 0.2 mol), dioxane (70 g) and dimethylsulfate (28 g = 0.22 mol) were heated on a steam bath under reflux for 45 minutes. The solvent was removed in vacuo on a steam bath, the residue dissolved in 20 ml of water and the product precipitated by the gradual addition of 80 g of 25% sodium hydroxide solution at 0°C. A small additional amount was obtained by extraction of the mother liquor with methylene chloride. The product melted at 60°C. 

Then, ethyl methyl(3-benzoylphenyl)cyanoacetate employed as an intermediate material is prepared as follows The sodium derivative of ethyl (3-benzoylphenyl)cyanoacetate (131 g) is dissolved in anhydrous ethanol (2 liters). Methyl iodide (236 g) is added and the mixture is heated under reflux for 22 hours, and then concentrated to dryness under reduced pressure (10 mm Hg). The residue is taken up in methylene chloride (900 cc) and water (500 cc) and acidified with 4N hydrochloric acid (10 cc). The methylene chloride solution is decanted, washed with water (400 cc) and dried over anhydrous sodium sulfate. The methylene chloride solution is filtered through a column containing alumina (1,500 g). Elution is effected with methylene chloride (6 liters), and the solvent is evaporated under reduced pressure (10 mm Hg) to give ethyl methyl(3-benzoylphenyl)cyano-acetate (48 g) in the form of an oil. 

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