Phosphoryl chloride , preparation

Chloro-2,S-dimethylpyrazine was not isolated from the reaction of DL-alanine anhydride with a mixture of phosphoryl chloride and phosphorus pentachloride, but the reaction gives a poor yield of (48, X = Q) and a small quantity of (48, X = OH). Gallagher et al. (282) found that DL-phenylglycine with phosphoryl chloride gave 2,5-dichloro-3,6-diphenylpyrazine and 3-hydroxy-2,5-diphenyl-pyrazine (presumably formed by loss of the elements of hydrogen chloride from an intermediate 2-chloro-5-hydroxy-3,6-diphenyldihydropyrazine) and Dunn et al. (95) from DL-leucine anhydride and phosphoryl chloride prepared flavacol, 3-hydroxy-2,5-diisobutylpyrazine, and a mature of chloropyrazines, whereas Ohta (101) used phosphoryl chloride and phosphorus pentachloride and obtained flavacol and a little 2[Pg.26]

Various inorganic, organic, and organometaUic compounds are known to cataly2e this polymerization (4,8,9). Among these, BCl is a very effective catalyst, although proprietary catalysts that signiftcandy lower polymerization temperature from the usual, sealed-tube reaction at 250°C are involved in the industrial manufacture of the polymer. A polycondensation process has also been developed for the synthesis of (4) (10—12). This involves elimination of phosphoryl chloride from a monomer prepared from (NH 2 04 and PCl. ... 

The reaction of 2,2 -bipyrrole with orthoformic acid triethyl ester in the presence of phosphoryl chloride (POCI3) produced a compound which gave the H NMR spectrum 5. Which compound has been prepared ... 

In an effort to prepare 1 2-dihydropapaverine, Buck dehydrated with phosphoryl chloride, and subjected the product (V) to catalytic reduction, followed by the action of phosphorus pentachloride in the cold. The final product was assumed to be 1 2-dihydropapaverine but Young and Robinson interpret this synthesis differently, and their formulae (V) and (VI) are given above, the final product being 3 4-dihydropapaverine (VII), which Buck thus prepared for the first time in a crystalline condition, m.p. 97-8° picrate, m.p. 151° perchlorate, m.p. 238° dec.). 

The phosphate ester, prepared either through phosphoramidite or phosphoryl chloride protocols, is cleavable by photolysis (350 nm, benzene, 83-87% yield)." ... 

In 1949, Comforth showed that preparation of 2,5-disubstituted oxazoles was not limited to diaryloxazoles through condensation of aldehydes (benzaldehyde, n-hept-aldehyde) with a-hydroxy-amides (lactamide). The intermediate oxazolidone 13 were converted into oxazoles 14 on warming with phosphoryl chloride. ... 

The ureas, e.g. 28 (R = NMe2), derived from the corresponding 2-(l-arylviny )benzylamines by reaction with (dimethylamino)carbamoyl chloride (Me2NCOCl) in the presence of triethyl-amine, undergo cyclization in refluxing phosphoryl chloride to the 5-aryl-3-(dimethylamino)-l//-2-benzazepin-3-amines. e.g. 29a.84 Prepared similarly are the 3-(4-methylpiperazin-l-yl) compound 29b and the 3-methyl derivative 29c from the corresponding urea and amide, respectively. 

The first dibenz[/>,e]azepine 23 was prepared by cyclization of amidine 22 with phosphoryl chloride in refluxing nitrobenzene.103... 

The pyrimidobenzazepinones 15 (see Section 3.2.1.5.6.) on treatment with phosphoryl chloride yield the 1-chloro derivatives 16 which are precursors for the preparation of 1-substituted pyrimido[5,4-c/]bcnzazepines, e.g. 17.7S... 

Nucleophilic processes that generate chloroindoles are largely confined to the displacements of oxy functions and Sandmeyer reactions of diazo-nium salts [81 H( 15)547]. A low yield of 2-chloroindole was obtained by a reaction sequence that involved treatment of oxindole with phosphoryl chloride, and then treatment of the Vilsmeier salt with sodium bicarbonate [66JOC2627 86H(24)2879]. It is, however, much better to prepare this compound from 2-lithioindole (92JOC2495). With phosphoryl chloride and dimethylformamide ethyl l-hydroxyindole-2-carboxylate failed to give the expected 3-formyl derivative. Instead there was a 50% yield of the 3-chloro derivative (84CPB3678). Diazonium salts have been used as precursors in... 

In the Meisenheimer reaction of quinoline 1-oxides chlorine atoms usually enter the 2-and 4-positions, but not exclusively. 2,4-Dibromoquinoline 1-oxide was 6-chlorinated (57MI1), and the 5- and 6-nitroquinoline 1-oxides were 3-chlorinated to some extent (44JOC302). This reaction with phosphoryl chloride-phosphorus pentachloride has also been used in the preparation of chlorinated phenanthrolines (88YZ1148). 

The mechanism of the condensation in Part D probably involves thioformylation of the metallated isocyanoacetate followed by intramolecular 1,1-addition of the tautomeric enethiol to the isonitrile. This thi2izole synthesis is analogous to the formation of oxazoles from acylation of metallated isonitriles with acid chlorides or anhydrides. " Interestingly, ethyl formate does not react with isocyanoacetate under the conditions of this procedure. Ethyl and methyl isocyanoacetate have been prepared in a similar manner by dehydration of the corresponding N-formylglycine esters with phosgene and trichloromethyl chloroformate, respectively. The phosphoryl chloride method described here was provided to the submitters by Professor U. Schollkopf and is based on the procedure of Bohme and Fuchs. The preparation of O-ethyl thioformate in Part C was developed from a report by Ohno, Koi/.uma, and Tsuchihaski. " ... 

A comprehensive review of the preparation, reactions, and n.m.r. spectra of phosphorus-fluorine compounds has appeared. This year s literature has been notable for the first detailed applications of ab initio SCF-MO calculations to the problems of bonding in halogenophosphines and their derivatives. - Comparison of the results of such theoretical calculations with experimental data obtained from photoelectron spectra shows a good correlation in the case of phosphorus trichloride and phosphoryl chloride, and of phosphorus trifluoride and its borane complex. ... 

General preparative procedures for the preparation of A -alkyl phos-phoramidic dichlorides (10) and A TV -dialkyl phosphorodiamidic chlorides (11) from the appropriate amine and phosphoryl chloride have been described. With weakly basic amines, pyrophosphoryl chloride was... 

The factors affecting the preparation of the cyclic chlorophosphazenes from phosphorus pentachloride and ammonium chloride continue to receive attention. For example, the yields and reaction times for the preparation of the series, (NPCla) ( — 3—7), varied with the fineness of the ammonium chloride, the nature and volume of the solvent, and added catalysts such as phosphoryl chloride. A procedure, giving due consideration to these factors, was described for the preparation of N3P3CI6 in good yield (88% of cyclic products) and in a relatively short time (2J h). The cyclic chlorophosphazenes can be obtained in even shorter times ca. 10 min) by addition of four moles of pyridine to remove the hydrogen chloride formed ... 

Carius (8) replaced the oxygen in phosphoryl chloride by sulfur. This may be somewhat analogous to the replacement of oxygen in a carbonyl group by sulfur using phosphorus pentasulfide. Prinz (8) used thionyl chloride in his reaction with phosphorus sulfide and De Fazi (2) used carbon tetrachloride in a very interesting preparation of this important intermediate. 

Diethyl chlorophosphate can also be prepared from ethyl alcohol and phosphoryl chloride in the presence of base, but the method shown is reported to give better yields. The intermediate diethyl chlorophosphate has been condensed with nitrophenol in a manner similar to that used for parathion (Equation 39). 

No details are given for scheme A. Presumably one could use the phosphoryl chloride instead of the fluoride. Scheme B, in which ethyl chloride is formed, was run in boiling xylene using equimolar quantities of the reactants. Michaelis (33) has partially described the preparation of starting materials from secondary amines with phosphorus oxychloride and also ethyl dichlorophosphate. Schrader (38) obtained alkyl and amido fluophosphates by reaction of the corresponding chlorophosphates with sodium fluoride in aqueous or alcoholic solution. 

An explosion occurred immediately after pouring and capping of the chloride recovered from preparation of ferrocene-1,1-dicarbonyl chloride. The storage bottle contained phosphoryl chloride recovered from similar preparations and which had been stored for some 3 months. No explanation was apparent. 

The first report on the reaction of D-pseudoephedrine 66 with phosphoryl chloride appeared as early as 1962 [49], More recently it was found that this condensation gave 2-chloro-l,3,2-oxazaphospholidine 2-oxides 67 as a single diastereomer which was subsequently esterified with racemic aldehyde cyanohydrins 68 without racemization at the phosphorus atom. The prepared diastereomeric esters 69 were used as substrates for the asymmetric synthesis of optically active cyanohydrins 72, which involves the intermediate formation of the tertiary esters 70, as shown in Scheme 22 [50],... 

A number of 1,3,2-diazaphospholidinc derivatives 264-265 having (5S)-1,3-diaza-2-phospha-2-oxo-3-phenylbicyclo[3.3.0]octene moiety (labeled as P) were prepared using diastereomerically pure (5.S)-1,3-dia/a-2-chloro-2-phospha-2-oxo-3-phenylbicyclo[3.3.0]octane (263) as a key substrate. Its preparation was in turn based on the reaction of phosphoryl chloride with (-)-197 (Scheme 63) [96-100]. 

With excess water, complete hydrolysis of PC15 yields H3P04 and HCl. Phosphoryl chloride can also be prepared by oxidizing PC13 or by the reaction of P4O10 with PC15. 

The second approach (224-226) employs O-methylhexadehydroyohimbine (420), prepared from spiroindeno-2-(l -tetrahydro-0-carboline)-l-onederivative 416 by photolysis and subsequent reduction, as the key intermediate. The side product (418) of the photolysis was also utilized for the preparation of 420 via subsequent phosphoryl chloride treatment and sodium borohydride reduction. Birch reduction of 420 resulted in enol ether 421, which could be transformed to 15,16-didehydroyohimbinone (410), prepared previously by Szantay et al. (74, 221) as a universal precursor of the synthesis of yohimbine-type alkaloids. 

MethyM-cthoxycarbonyl-5-bcnzoyl-hydrazino-l //-pyrazole 274, prepared by reacting benzoyl chloride and 3-methyM-cthoxycarbonyl-5-bcnzoyl-hydrazino-l //-pyrazole hydrochloride 273, in the presence of pyridine in acetonitrile, has been cyclized with phosphoryl chloride in benzene or toluene to give 7-ethoxycarbonyl-6-methyl-3-phenyl-l //-pyrazolo[5,l -/ 1,2,4 triazolc 55. This compound has been also synthesized through cyclization of... 

In a Vilsmeier-Haack-Amold reaction, A/,Ar-disubstituted amino-methylenemalonates (329) were prepared in good yields from the sodium derivative of diethyl malonate or from diethyl malonate in the presence of triethylamine in benzene or toluene at a temperature below 20°C with imidoyl chlorides, which were prepared in situ from N./V-disubstituted formamides and phosphoryl chloride (63BRP917436). Instead of diethyl malonate, diethyl ethoxymagnesiummalonate could also be used (63 BRP917436). 

Arylamino)quinoline-3-carboxylates (693) were prepared by the cyclization of /V -aryl(arylamino)methylenemalonamates (252) on the action of phosphoryl chloride in boiling benzene or of phosphorus pentoxide in refluxing xylene (46JA1246). Phosphoryl chloride proved to be a more effective cyclization agent than phosphorus pentoxide. This method could not be applied for the preparation of 4-alkylaminoquinoline-5-carbox-ylates. 

The isomeric 1,3-dioxino[4,5-/i]quinoline (698) and l,3-dioxino[5,4-/i]quinoline (700, R = Me) were prepared by cyclization of the appropriate N-( 1,3-benzodioxanyl)aminomethylenemalonates (697 and 699, R = Me) in boiling phosphoryl chloride for 12 hr (72MI5). While the methyl derivative of compound 699 (R = Me) readily gave l,3-dioxino[5,4-/i]quinoline (700, R = Me), the unsubstituted and chloro derivatives (699, R = H, Cl) could not be cyclized by heating in phosphorus chloride, even if triethylamine, SnCl4, or PC15 was also present (72MI5). 

Nakagome and co-workers effected the successful cyclization of N-ethyl-N-arylaminomethylenemalonates (749) in poly phosphoric acid, prepared from orthophosphoric acid and phosphorus pentoxide in polyphosphate ester (PPE), prepared from phosphorus pentoxide and anhydrous diethyl ether in chloroform in phosphoryl chloride on the action of boron trifluoride etherate on the action of acetic anhydride and concentrated sulfuric acid or on the action of phosphorus pentoxide in benzene [71GEP2033971, 71JHC357 76JAP(K) 18440]. Depending on the work-up process, l-ethyl-4-oxoquinoline-3-carboxylates (750, R1 = Et), l-ethyl-4-oxoquinoline-3-carboxylic acids (750, R2 = H) and 3-ethoxycarbonyl-4-chloroquinolinium iodides (751) were obtained. Only the cyclization of... 

Aqui et al. investigated the cyclization of diethyl A-(3-substituted phe-nyl)aminomethylenemalonates (251) under different cyclization conditions (75JHC557). For cyclization, they applied a 4 7 mixture of concentrated sulfuric acid and acetic anhydride, polyphosphoric acid, polyphosphate (prepared from phosphorus pentoxide and diethyl ether in chloroform), phosphoryl chloride, and Dowtherm A (see Table VI). They found the most effective cyclization conditions were thermal cyclization (heating in Dowtherm A) and polyphosphate. 

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