Polyphosphoric acid, reaction with

A rather more complex tertracyclic indole based compound lowers blood pressure by selective blockade of a 1-adrenergic receptors. Reaction of the anion from indole (72-1) with butyrolactone (72-2) leads to the scission of the carbon-oxygen bond in the reagent and the formation of the alkylated product (72-3). The acid is then cyclized onto the adjacent 2 position to give the ketone (72-4) by treatment with a Lewis acid such as polyphosphoric acid. Reaction with bromine then leads to the brominated ketone (72-5). This is subjected to reductive alkylation with ethylene... 

Moore and Snyder121 have employed the Schmidt reaction to determine the structure of the hydrocarbon (71), which is one of the products of the self-condensation of acetophenone in polyphosphoric acid. Treatment with hydrogen bromide and dimethyl sulfoxide (DMSO) gives the fluorenol (72), which yields a mixture of 1-methyl-2,4,6-triphenylphenanthridine (73) and 10-methyl-6,7,9-triphenyl-phenanthridine (74) when treated with hydrazoic acid. 

This method is also applicable to pyrimidines with monoalkylated 6-amino groups.206 If the reaction is performed at 100°C with polyphosphoric acid,207 with polyphosphoric acid esters,208 or with trimethylsilyl trifluoroacetate,209 the 6-carboxy group will be retained. 

When a vinylphosphonic ester (315) (R = CH2CH2R ) is heated with polyphosphoric acid or with phosphoric acid in toluene, cyclization occurs with the elimination of R" CH2CH20H. The reaction, thought to proceed through the steps illustrated, provides 17-70% yields of 2H-1,2-benzoxaphosphorin 2-oxides (316) . 

CAS 68131-71-5 68308-31-6 EINECS/ELINCS 268-624-8 269-643-4 Synonyms Polyphosphoric acids, compds. with triethanoiamine Poiyphosphoric acids, esters with triethanoiamine Poiyphosphoric acid, triethanoiamine ester Triethanoiamine poiyphosphate Triethanoiamine poiyphosphate ester Definition Reaction prod, of triethanoiamine and poiyphosphoric acid Uses Emuisifier in cosmetics Reguiatory Canada DSL Manuf./Distrib. Somerset Cosmetic Co. 

In the reverse reaction, thioheteroaryl amides reacted under reflux in alcohol with haloketones or aldehydes to give the corresponding 2-heteroarylthiazole derivatives (238, 271, 482, 550, 751, 765, 776, 781). 2,2 -Bithiazoles (4,4 -disubstituted) have been obtained in 80 to 90% yield by cyclocondensation of 1 mole rubeanic acid with 2 moles of a-bromoketones in polyphosphoric acid at 95 to 135 C (780). Some multiheteroaryl substituted thiazoles have been also reported (704). 

Whereas the above reactions are appHcable to activated aromatics, deactivated aromatics can be formylated by reaction with hexamethylenetetramine in strong acids such as 75% polyphosphoric acid, methanesulfonic acid, or trifluoroacetic acid to give saUcylaldehyde derivatives (117). Formyl fluoride (HCOF) has also been used as formyl a ting agent in the Friedel-Crafts reaction of aromatics (118). Formyl fluoride [1493-02-3] in the presence of BF was found to be an efficient electrophilic formyl a ting agent, giving 53% para-, 43% ortho- and 3.5% meta-tolualdehydes upon formylation of toluene (110). 

Polyphosphoric acid, P2O5, POCl, and PCl are suitable phosphorylatiag agents. Reaction of an alkyl sulfate with sodium pyrophosphate has also been reported for preparation of alkyl pyrophosphates (77). In general, phosphorylation leads to a mixture of reaction products that are sold without further separation. Thus, when lauryltri(ethyleneoxy)ethanol reacts with 0.3 mol of P2O5 at 50°C and is neutralized with 50% aqueous NaOH, the reaction mixture contains the foUowiag products ... 

These mechanisms are characterized by the relative magnitudes of the heats of reaction, solution, or adsorption (see Adsorption, separation). AH useflil drying mechanisms are exothermic. Phosphoms pentoxide is a Class 1 drying agent that reacts with water to form a polyphosphoric acid (2) ... 

Tetramethoxyisoflavone (5) was the target of the cyclisation reaction of 3,4-dimethoxy-phenol (7) with formyl-(3,4-dimethoxyphenyl)acetic acid (2) in the presence of polyphosphoric acid. 

Jones and Civcir prepared a variety of alternating oligomeric furanipyridine compounds and studied their NMR chemical shifts as well as the pKa values for the corresponding conjugate acids. All of these compounds were synthesized by Paal-Knorr reactions of 1,4-diketones with hot polyphosphoric acid. A representative example is the conversion of 24 into 25 in 82% yield. ... 

In 1909, Robinson demonstrated the utility of acylamidoketones as intermediates to aryl-and benzyl-substituted 1,3-oxazoles through cyclization with sulfuric acid. Extension of sulfuric acid cyclization conditions to alkyl-substituted oxazoles can give low yields, for example 10-15% for 2,5-dimethyl-l,3-oxazole. Wiegand and Rathbum found that polyphosphoric acid can provide alkyl-substituted oxazoles 4 in yields equal to or greater than those obtained with sulfuric acid. Significantly better yields are seen in the preparation of aryl- and heteroaryl-substituted oxazoles. For example, reaction of ketoamides 5 with 98% phosphoric acid in acetic anhydride gives oxazoles 6 in 90-95% yield. ... 

An interesting synthesis of quinolizidines was achieved using a vinylogous variation of the Bischler-Napieralski reaction. Angelastro and coworkers reported that treatment of amide 26 with PPSE (polyphosphoric acid trimethylsilyl ester) followed by reductive... 

The hydroxamic acid function in most alicyclic and aromatic compounds is stable to hot dilute acid or alkali, and derivatives cannot undergo normal base-catalyzed Lessen rearrangement. Di Maio and Tardella," however, have shown that some alicyclic hydroxamic acids when treated with polyphosphoric acid (PPA) at 176°-195° undergo loss of CO, CO.2, or H2O, in a series of reactions which must involve earlj fission of the N—0 bond, presumably in a phosphoryl-ated intermediate. Thus, l-hydroxy-2- piperidone(108) gave carbon monoxide, 1-pyrroline (119), and the lactams (120 and 121). The saturated lactam is believed to be derived from disproportionation of the unsaturated lactam. 

Dehydrogenation of the later with Pd/C gave 329 (82AP901). On the other hand, reaction of indoline or 2-methylindoline with acrylic acid or crotonic acid by heating in presence of polyphosphoric acid gave 330 and 331 (79JHC949) (Scheme 59). 

B) 40 g of N-chloroacetyl-2-benzylaniline are heated for 2 hours at 120°C together with 50 ml of phosphorus oxychloride and 320 g of polyphosphoric acid. Next the reaction mixture is poured on ice and extracted with benzene. The extract is washed and dried on sodium sulfate and the benzene distilled off. The product obtained (31 g) yields after recrystallization 24 g of 6-chloromethyl-morphanthridine of MP 136° to 137°C. 

On saponification l-(2-methoxycarbonylphenyl)pyrrole yields l-(2-carboxyphenyl)pyrrole, m.p. 106-107°, which on reaction with polyphosphoric acid at 70° is cyclized to 9-keto-9H-pyrrolo-(l,2-a)indole in 28-32% yield. Through the choice of the appropriate amine and acetal components, the substituted l-(2-meth-oxycarbonylphenyl)pyrroles become readily available intermediates in the preparation of a variety of derivatives of the pyrrolo( 1,2-a) indole ring system. 

The only 5//-1,3,6-triazonine system which has been reported and is fully supported by spectral data and elemental analysis is obtained by reaction of the imine 1 with chloroacetic acid and polyphosphoric acid.22 From a mixture of products, 2-chloro-6-(chloromethyl)-13-phenyl-dibenzo[e/, h [, 3,6]triazonine (2) was separated by silica-gel flash chromatography in poor yield. 

This ring system may be prepared from 527 by condensation with ami-drazone or aminoguanidine derivatives to afford 528, which on reaction with polyphosphoric acid gave imidaz[5, -/][ ,2,4]triazin-4(2//)one 529... 

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