Phosphorus oxychloride, as solvent

A recent patent describes the formation of carbonimidoyl dichlorides in the reaction of several aliphatic and aromatic isocyanates with phosphorus pentachloride. This reaction can be conducted using phosphorus oxychloride as solvent, or without a solvent however, only from aliphatic isocyanates diisocyanates are good yields of... 

Dihalophenyl sulfones may be obtained by chlorination of 4-haloaryl sulfones 1 by treatment with chlorine in the presence of iodine using a mixture of chlorosulfonic acid and phosphorus oxychloride as solvent. The reaction afforded the corresponding 3-chloro derivative 2 (Equation 1). ... 

CH3)2N]3P0. M.p. 4°C, b.p. 232"C, dielectric constant 30 at 25 C. Can be prepared from dimethylamine and phosphorus oxychloride. Used as an aprotic solvent, similar to liquid ammonia in solvent power but easier to handle. Solvent for organolithium compounds, Grignard reagents and the metals lithium, sodium and potassium (the latter metals give blue solutions). 

The Meth-Cohn quinoline synthesis involves the conversion of acylanilides 1 into 2-chloro-3-substituted quinolines 2 by the action of Vilsmeier s reagent in warmed phosphorus oxychloride (POCI3) as solvent. ... 

The reaction of benzo-2-furancarboxylic acid with thiosemicarbazide under microwave conditions enables the use of an equivalent amount of phosphorus oxychloride and a short reaction time <2003SC2891 >. Moreover, solvent-free conditions are achieved when acidic alumina is used as dehydrating agent under microwave heating in the reaction of alkyl carboxylic acids with thiosemicarbazide <2000SC3031>. 

Anthrapyrimidine and its substituted derivatives are obtained by condensation of 1-aminoanthraquinone (or its derivatives) with formamide or aqueous form-aldehyde/ammonia in the presence of an oxidant, such as ammonium vanadate or m-nitrobenzosulfonic acid. A newly developed, more simple route proceeds via formamidinium chloride, which is prepared from 1-aminoanthraquinone with di-methylformamide and thionyl chloride or phosphorus oxychloride. Cyclization in a solvent in the presence of ammonium acetate affords the desired product ... 

The isoquinoline framework is derived from the corresponding acyl derivatives of P-hydroxy-P-phenylethylamines. Upon exposure to a dehydrating agent such as phosphorus pentaoxide, or phosphorus oxychloride, under reflux conditions and in an inert solvent such as decalin, isoquinoline frameworks are formed. 

The major advantages of this procedure over the enol sulfonate procedure lie in the availability of diethyl 2-chloro-2-cyclopropylethene-l,l-dicarboxylate from the corresponding acylmalonate and phosphorus oxychloride, and the fast, homogeneous, decarboxyl ative elimination reaction of the triethylamine salt of the half-ester in dry organic solvents. The conditions described here, with slight modifications (overnight treatment), have been used for a variety of g-chloro alkyl idene/aryl idene malonates as shown in Table I. 

There has been some controversy in the literature over the proper interpretation of reactions in solvents such as phosphorus oxychloride. Drago and coworkers18 have suggested the "coordination model" as an alternative to the solvent system approach. They have stressed the errors incurred when the solvent system concept has been pushed further than warranted by the facts. In addition, they have pointed out that iron(lll) chloride dissolves in triethyl phosphate with the formation of letrachloro-... 

Meek and Drago8 showed that the reaction between tetramethylammonium chloride and iron(III) chloride can take place just as readily in triethyl phosphate, OP(OEt), as in phosphorus oxychloride, OPCl,. They suggested that the similarities in physical properties of the two solvents, principally the dielectric constant, were more impor tant in this reaction than the difference in chemical properties, namely, the presence or absence of autoionization to form chloride ions.9... 

Most of the solvents on the List are stable in the presence of water for long periods, but there are a few solvents that react with water. They do so either rather slowly but more rapidly in the presence of basic or acidic catalysts, such as certain esters, or rapidly, such as acetic anhydride or phosphorus oxychloride. These are noted by reacts1 in Table 4.6. Many solvents, on the other hand, are quite hygroscopic, and unless kept over a drying agent, such as molecular sieves... 

Solvents that meet all or most of the criteria are propylene carbonate, dimethyl sulfoxide, 4-butyrolactone, acetonitrile, sulfur dioxide, thionyl chloride, and phosphorus oxychloride. Certain other solvents, with fairly low s values, such as tetrahydrofuran, dimethoxyethane, and 1,3-oxolane are used in conjunction with a high s solvent, in order to reduce the viscosity without impairing excessively the other desirable properties of the co-solvent. All these solvents are on the List, with properties shown in the tables mentioned. Commercial implementation of such batteries has been highly successful, with energy densities of primary dischargeable batteries of 0.3 W h g 1 or 0.5 W h cm 3 and a self discharge rate of < 2% per year of the open-circuit battery being achieved. 

Other solvents such as carbon disulfide 48>1 9 117 and sj/m-tetrachloro-ethane118 have been found successful in the cyclization stage. Another method of separating the phosphorus compounds is by the use of petroleum ether, in which the acid chloride, but not the phosphorus oxychloride, is soluble.119... 

Selenium oxychloride is not the only inorganic solvent used for liquid lasers, several studies use as solvent phosphorus oxychloride, POCl3 (Blumenthal et al., 1968 Brecher and French, 1969 Brinkschulte et al., 1972). Although this solvent is a worse host for ionic salts due to its lower dielectric constant, it is much more attractive for liquid laser uses since it is far less toxic and corrosive than SeOCl2. The approach for the preparation of POCl3 solutions is slightly... 

The El reaction is not ideal for the dehydration of primary or secondary alcohols since vigorous heating is needed to force the reaction and this can result in rearrangement reactions. In alternative methods which are useful, reagents like phosphorus oxychloride (POCl3) dehydrate secondary and tertiary alcohols under mild basic conditions using pyridine as solvent (Following fig.). The phosphorus oxychloride serves to activate the alcohol,... 

Allyloxy-2,3-dimethylquinoline on heating without a solvent at 200° for only 30 minutes afforded in yields as high as 92% a product with a quinolone structure. Confirmation of this formulation came from the following series of transformations (1) treatment with phosphorus oxychloride which gave the 4-chloro compound and... 

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