Concentrated Hydrochloric Acid Dichloride

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... 

Method A. Cool a solution of the nitrate-free dichloride, prepared from or equivalent to 5 0 g. of palladium or platinum, in 50 ml. of water and 5 ml. of concentrated hydrochloric acid in a freezing mixture, and treat it with 50 ml. of formahn (40 per cent, formaldehyde) and 11 g. of the carrier (charcoal or asbestos). Stir the mixture mechanically and add a solution of 50 g. of potassium hydroxide in 50 ml. of water, keeping the temperature below 5°. When the addition is complete, raise the temperature to 60° for 15 minutes. Wash the catalyst thoroughly by decantation with water and finally with dilute acetic acid, collect on a suction filter, and wash with hot water until free from chloride or alkali. Dry at 100° and store in a desiccator. 

Cool the filtrate (A) to 5-10° and add concentrated hydrochloric acid dropwise and with vigorous stirring (FUME CUPBOARD hydrogen cyanide is evolved) to a pH of 1-2 (about 50 ml.) a crude, slightly pink 3-indoleacetic acid is precipitated. The yield of crude acid, m.p. 159-161°, is 20 g. Recrystallise from ethylene dichloride containing a small amount of ethanol 17 -5 g. of pure 3 indoleacetic acid, m.p. 167-168°, are obtained. 

TeCl4 in concentrated hydrochloric acid reacts with arenediazonium chlorides giving bis(arenediazonium) hexachlorotellurates that are decomposed by copper powder in acetone to give diaryltellurium dichlorides in low to medium yields. ... 

A 500-ml reaction flask was charged with the step 1 product (43.1 mmol), the poly condensate of 4,4 -dichlorobenzophenone-2,2-bis(4-hydroxyphenyl)-1,1,1,3,3,3-hexa-fluoropropane (Mn 11,200 Da 1.80 mmol), bis(triphenylphosphine) nickel dichloride (1.35 mmol), sodium iodide (5.85 mmol), triphenylphosphine (18 mmol), and zinc (108 mmol). The mixture was dried under vacuum and then treated with 87 ml of N,N-dimethylacetamide and kept in the temperature range of 70-90°C. After 3 hours the mixture was diluted with 200 ml of V,V-dimethylacetamide and insoluble components removed by filtration. The filtrate was then added to 1.5 liters of methanol containing 10 vol% concentrated hydrochloric acid to precipitate the polymer. After collecting, the precipitate was dried to obtain 28.5 g of product having polyhydroxyl groups. 

Samples of the niobium (V) chloride or niobium (V) bromide-pyridine reaction mixtures were hydrolyzed in concentrated hydrochloric acid. Aliquots were diluted and neutralized with sodium carbonate to a pH of approximately 8. Sodium tetraphenylborate(III) solution then was added and a precipitate of l-(4-pyridyl) pyridinium tetraphenylborate(III) was produced. The precipitate was filtered and extracted with concentrated hydrochloric acid. The ultraviolet absorption spectrum of the extract is shown in Figure 3 for comparison with the spectrum of a known sample of l-(4-pyridyl) pyridinium dichloride in dilute hydrochloric acid. 

Diphenyl selenium dichloride, (C6H5)aSeCl2, is formed when diphenyl selenoxide is treated with hydrochloric acid. It crystallises in glistening prisms, M.pt. 179° to 180° C.4 A similar product is obtained when diphenyl selenide is dissolved in an excess of concentrated nitric acid and concentrated hydrochloric acid added.5... 

Di-o-tolyl selenium dichloride, (C7H7)2SeCl2,2 is a white product, M.pt. 152°-to 153° C. with decomposition, formed from the corresponding oxide by the action of concentrated hydrochloric acid. 

A warm solution of 1-53 grams of the dihydroxide in 4 c.c. of glacial acetic acid is treated with a mixture of 2 c.c. of concentrated hydrochloric acid and 3 c.c. of acetic acid. The dichloride separates and is recrystallised from 80 c.c. of acetic acid, 1 6 grams of almost colourless, bulky, feathery needles being obtained. The product turns yellow at about 125° C. and melts at 131° to 132° C. A large bulk of water or dilute sodium hydroxide converts the dichloride to the dihydroxide, and aqueous potassium bromide (2 mols.) converts it to the dibromide. Attempts to form the dichloride by the action of chlorine on the selenide give a white crystalline compound of melting-point 186° to 187° C., which contains chlorine not replaceable by the action of aqueous sodium hydroxide. 

Treatment of the hydronitrates in aqueous solution with sodium carbonate causes evolution of carbon dioxide. Evaporation to dryness, followed by extraction with alcohol or benzene, then yields oils which are probably the selenoxides. These oils with concentrated hydrochloric acid are converted into white solids, crystallisable from benzene, xylene, alcohol or dry ether. These solids are the dichlorides of the original selenides, and when prepared by this method their melting-points are as follows Phenyl methyl selenium dichloride, M.pt. 122° C. phenyl ethyl selenium dichloride, M.pt. 64° to 65° C. diphenyl selenium dichloride, M.pt. 142° C. 

A mixture of 288 g (4 mols) of isobutyraldehyde, 288 g of methanol was cooled to 10°C and 170 g (2 mols) of 36.6% formalin containing 8.5 g (3% based on isobutyraldehyde) of sodium hydroxide was added dropwise over a 55 minute period to produce alpha,alpha-dimethyl-beta-hydroxy-propionaldehyde. The mixture was stirred for an additional 2 hours at 10-15°C and then contacted with acetic acid to neutralize the catalyst. The excess isobutyraldehyde and methanol were stripped off at a kettle temperature of 50°C at 25 mm. To the residual a,a-dimethyl-beta-hydroxypropionaldehyde a mixture of 260 ml of methanol and 2 g (0.75%) sodium cyanide was added and the solution cooled to 10°C before adding 59.4 g (2.2 mols) of hydrogen cyanide dropwise over a 35 minute period to produce a,y-dihydroxy-p,p-dimethylbutyronitrile. The mixture was stirred at 10°C for one hour period and then contacted with acetic acid to neutralize the catalyst before stripping off the excess methanol to a kettle temperature of 45°C at 18 mm. The crude cyanohydrin was then hydrolysed by heating with 4 mols of concentrated hydrochloric acid at 80°C for 2 hours, then diluting with an equal volume of water and heating at 100°C for an additional 8 hours. The aqueous mixture was extracted continuously with ethylene dichloride. The solvent was... 

Aryl 2,4-dihydroxyphenyl tellurium dichlorides kept in acetic anhydride in the presence of a drop of concentrated hydrochloric acid formed aryl 2,4-diacetoxyphenyl tellurium dichlorides1. 

Diacctoxyphenyl 4-Methoxyphenyl Tellurium Dichloride To 0.21 g (0.5 mmol) of 2,4-dihydroxyphenyl 4-methoxyphenyI tellurium dichloride are added 5 ml of aeetie anhydride followed by 1 drop of concentrated hydrochloric acid. The mixture is gently shaken until it is homogeneous and is then allowed to stand at 20° for 24 h. The mixture is then cooled in an ice bath, water is added dropwise to the stirred mixture, the precipitated product is filtered off, and recrystallized from benzcne/petroleum ether (b.p. 50-70°) yield 0.22 g (88%) m.p. 167°... 

Phenoselenatellurin 10,10-Dichloride 3.0 g (60 mmol) of 2-phenylselenophenyl tellurium trichloride, 3.0 g (23 mmol) of aluminum trichloride, and 20 ml of 1,2-dichlorobenzene are placed in a 100 m/round bottom flask fitted with a reflux condenser and a mechanical stirrer. The mixture is heated under gentle reflux in an oil bath for 2 h, cooled, and extracted with two 50-ml portions of petroleum ether to remove dichlorobenzene. The oily residue is treated with a mixture of 100 ml of ice/water and 50 ml of Concentrated hydrochloric acid, the yellowish-grey residue is filtered, washed with water, then with 10 m/ of carbon tetrachloride, and is dissolved in 300 ml of hot acetone. The solution is filtered, concentrated to a volume or about 30 m/, and the precipitated yellow solid is filtered off. The solid is dissolved in 300 m/ of warm dichloromethane, the solution is filtered, the filtrate is concentrated to a volume of about 30 ml, and the yellow crystals are collected yield 0.92 g (33%) m.p. 268-271°. 

It is soluble in concentrated hydrochloric acid, yielding a yellow solution of the carbonyl platinum dichloride. With alkalies it reacts as follows ... 

Bis[4-methoxyphenyl] Tellurium Dichloride A 0.2 molar solution of 4-methoxybenzenediazonium chloride is prepared from 24,6 g (0.23 mol) of aminobenzene, 150 ml of half concentrated hydrochloric acid, and 14 g (0,21 mol) of sodium nitrite in 20 ml of water. To the cooled and vigorously stirred diazonium salt solution are added 27 g (0.1 mol) of tellurium tetrachloride or 16 g (0.1 mol) of tellurium dioxide dissolved in 75 ml of concentrated hydrochloric acid. The temperature of the reaction mixture must not exceed — 5 during this addition. The mixture is stirred at — 5° for 20 min and then filtered. The filter cake is washed carefully with three 50 ml portions of acetone, then with diethyl ether, and finally with petroleum ether. The product, bis[4-methoxybenzenediazonium] hexachlorotellurate, is dried in air yield 52.8 g (86%). 

Treatment of 4-dimethylaminophenyl 4-RO-phenyl tellurium dibromides (R = CHj, C2H5, C(,H5) with concentrated hydrochloric acid yielded the corresponding tellurium dichlorides . 

Chlorophenoxatellurin 10,10-Dichloride A suspension of 2.0 g (6.4 mmol) of 2-aminophenoxateUurin in 5 ml of concentrated hydrochloric acid is diazotized at 0-5 with a solution of 0.4 g (5.8 mmol) of sodium nitrite in 4 ml of water. The diazonium salt solution is immediately filtered and poured into a solution of 2.0 g of copper(I) chloride in 10.2 ml of hydrochloric acid and the resultant mixture is boiled on a water bath for 30 min. The mixture is then cooled, filtered, the filter cake is washed with water, dried, and recrystallized from acetone yield 1.0 g (39%) m.p. 310°. 

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