Phosphorus pentachloride with alcohols

The products of the reactions of phosphorus pentachloride with the alcohols (109) are highly dependent upon the nature of as outlined... 

Method 2. Mix 1 0 g. of 3 5-dinitrobenzoic acid with 1 5 g. of phosphorus pentachloride in a small, dry test-tube. Warm the mixture gently over a small smoky fiame to start the reaction when the reaction has subsided (but not before), boil for 1-2 minutes or until the solid matter has dissolved. Pour the mixture while still liquid on a dry watch glass (CAUTION the fumes are irritating to the eyes). When the product has solidified, remove the liquid by-product (phosphorus oxychloride) by transferring the pasty mixture to a pad of several thicknesses of filter paper or to a small piece of porous tile. Spread the material until the liquid has been absorbed and the residual solid is dry. Transfer the 3 5 dinitrobenzoyl chloride to a test-tube, add 0-5-1 ml. of the alcohol, and continue as in Method 1. 

Beckmann rearrangement of benzophenone oxime to benz-anilide. Dissolve 2 g. of benzophenone oxime in 20 ml. of anhydrous ether in a small conical flask and add 3 g. of powdered phosphorus pentachloride (or 3 ml. of pure tbionyl chloride). Distil off the solvent and other volatile products on a water bath CAUTION ether), add 25 ml. of water, boil for several minutes and break up any lumps which may be formed. Decant the supernatant liquid, and recrystallise, in the same vessel, from boiling alcohol. The product is benzanilide, m.p. 163° confirm this by a mixed m.p. determination with an authentic specimen. 

Constitution. Pelletierine behaves as a secondary amine and the oxygen atom of the alkaloid is present in the form of an aldehyde group, since the base yields an oxime, convertible by the action of phosphorus pentachloride into a nitrile, b.p. 104-6°/13 mm., which is hydrolysed by caustic potash in alcohol to an acid, the ethyl ester of which is Loffler and Kaim s ethyl -2-piperidylpropionate. Pelletierine is not directly oxidisable to this acid. It also yields a liquid hydrazone, b.p. 130°/20 ram., which with sodium in alcohol at 136-70° reduces to dZ-eoniine. These reactions are explained by the following formulas, in which pelletierine is represented as -2-piperidylpropionaldehyde. 

Tropic Acid. The constitution of both tropic and atropic acids is known from syntheses by Ladenburg et al. from acetophenone. The ketone (I) by treatment with phosphorus pentachloride was converted into a-dichloroethylbenzene (II), and this, by the action of potassium cyanide in alcohol, into ethoxycyanoethylbenzene (III), which on hydrolysis yielded ethylatrolactic acid (TV). The latter was converted by strong... 

Two isomeric alcohols, known as vetivenol, also exist in the oil. By treatment with phosphorus pentachloride this mixture of alcohols is converted into a chloride, or mixture of chlorides, which on reduction yields an artificial vetivene, having the following characters —... 

With phosphorus pentachloride it yields myrtenyl chloride, CioHi Cl, which by reduction with sodium and alcohol yields pinene. 

Oxo-4,5-dihydro-l//-l,2,4-benzotriazepine-3-carboxylates8can be transformed into the acid chlorides 10 with phosphorus pentachloride and the crude products converted into various amides and esters 11 by treatment with amines and alcohols, respectively. Selected examples are given.347... 

The traditional method for transforming carboxylic acids into reactive acylating agents capable of converting alcohols to esters or amines to amides is by formation of the acyl chloride. Molecules devoid of acid-sensitive functional groups can be converted to acyl chlorides with thionyl chloride or phosphorus pentachloride. When milder conditions are necessary, the reaction of the acid or its sodium salt with oxalyl chloride provides the acyl chloride. When a salt is used, the reaction solution remains essentially neutral. 

Ethyl fumarate has been prepared from fumaric acid and ethyl alcohol, with or without sulfuric acid as catalyst,4 from silver fumarate and ethyl iodide,5 from silver maleate and ethyl iodide plus a trace of iodine,6 from ethyl maleate by the action of iodine,6 from ethyl maleate and phosphorus pentachloride,7 and by passing hydrogen chloride into a boiling absolute alcohol solution of malic acid.8... 

A weighed quantity of the oxime is dissolved in some cold ether, free from water and alcohol, and to the solution 1 -5 parts of finely powdered phosphorus pentachloride are gradually added. The ether is then removed by distillation and water Is added to the residue with cooling the ensuing precipitate is recrystallised from alcohol. Melting point 163°. 

Reactions. Saligenin [90-01-7] undergoes the typical reactions of phenols and benzyl alcohol. When heated above 100°C, it transforms into a pale yellow resinous material. Amorphous condensation products are obtained when saligenin reacts with acetic anhydride, phosphorus pentachloride, or mineral acids. Upon boiling with dilute acids, saligenin is converted into a resinous body, saliretin, a condensed form of saligenin. Condensation reactions of saligenin with itself in the absence of any catalysts and in the presence of bases have also been studied. 

Benzoyl chloride, [98-88-4], C6HbCOC1, mp, — 1°C bp, 197.2°C at 101.3 kPa df, 1.2070 n], 1.55369. Benzoyl chloride is a colorless liquid that fumes upon exposure to the atmosphere, has a sharp odor, and in vapor form is a strong lachrimator. It is decomposed by water and alcohol, and is miscible with ether, benzene, carbon disulfide, and oils. Benzoyl chloride may be prepared in several ways, including the partial hydrolysis of benzotrichloride, the chlorination of benzaldehyde, and from benzoic acid and phosphorus pentachloride. The most common method is the reaction of benzoic acid and benzotrichloride [98-07-7]. Since benzoic acid may be easily obtained from benzotrichloride, the latter is used as the sole raw material for large-scale production of benzoyl chloride. 

VI, obtained from stereospecific reactions of the corresponding optically active alcohol (11) with thionyl chloride, phosphorus pentachloride, etc., was not racemized under any of the reaction conditions. Monitoring the carbonyl absorption frequencies in the IR during these decarbonylations showed that the transformations II — III — IV took place during the conversion of V to racemic VI. Thus rearrangement or decomposition or both could be responsible for the racemization. 

Oxalvl Chloride. This diacid chloride is produced by the reaction of anhydrous oxalic acid and phosphorus pentachloride. The compound vigorously reacts with water, alcohols, and amines, and is employed for tile synthesis of agrochemicals, pharmaceuticals, and fine chemicals. 

Dibenzyl selenium dichloride,4 (C6H5.CH2)2SeCl2, occurs when an alcoholic solution of the dinitrate is treated with hydrogen chloride, or when benzylseleninic acid is treated with phosphorus pentachloride. It crystallises in colourless needles, M.pt. 134° to 135° C.5... 

If the diselenide acid is treated with phosphorus pentachloride the free acid chloride is not isolated, but the compound (HCl.Se.C6H4.COCl)2. The normal acid chloride, however, is formed by using thionvl chloride it crystallises from benzene or toluene in needles, M.pt. 178° to 174° C. If the hydrochloride, M.pt. 65c to 66° C., be boiled with methyl alcohol, a compound is obtained, M.pt. 74° to 75° C., which is the hydrochloride of the methyl ester of the diselenide acid, (Se.C6H4.COMe)2, which may be liberated by dilute sodium hydroxide. The free ester melts at 143° to 144° C. The corresponding ethyl ester melts at 129° to 130° C. and its hydrochloride at 91° to 92c C. Both esters may be formed also from the silver salt of the acid by heating with the alkyl iodide for two to three hours at 1X0° to 1203 C. 

Separation of o- and p-Toluenesulpbonic Acids.—The mixture prepared above is treated gradually with an equal weight of finely pulverised phosphorus pentachloride. When the reaction is complete, cold water is added, the whole being surrounded by a freezing mixture. The p-sulphonyl chloride separates as a solid (M.P. 69°) recrystallisable from alcohol. The o-sulphonyl chloride is an oily liquid (M.P. 10°), and is separated from the filtrate by means of a funnel. 

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