Alkylation with orthophosphoric acid

Benzyl-1-indanol 32, readily available in a few steps from 1-indanone, has been converted into 2-benzylindene 33 in various ways [66 - 68]. Treatment of 32 with orthophosphoric acid in chlorobenzene, for example, gives 33 as the sole product. However, use of polyphosphoric acid in the same solvent effects clean cyclodehydration of both 32 and 33 giving the mono-/uso-diindane 34 in high yield [65]. Several cenfro -alkylated derivatives of 34, including the methyl... 

Orthophosphoric and benzylphosphonic acids have been selectively alkylated with triethyl phosphite in a new synthesis of mono-, di-, and triethyl phosphates and of mono- and di-methyl phosphonates.62 A-Methylol carboxamides and sulphonamides react with trialkyl phosphites to give the phosphonate derivatives (78) and (80), respectively.63 However, the mechanism appears to be quite different in each case while the carboamides react by a transesterification-rearrange-ment pathway, the sulphonamides undergo elimination-addition via the imine (79). 

Figure 18.4 shows the structural formula of orthophosphoric acid as well as those of diphos-phoric and polyphosphoric acids, produced by polymerization of orthophosphoric acid with loss of water. These compounds form esters in which alkyl, alkenyl, and aryl hydrocarbon moieties are substituted for H most of the more common ones are esters of orthophosphoric acid. In this section,... 

The cleavage of tetrahydrofuran and its alkylated derivatives with halogen acids is an excellent method for the preparation of, A-dihalo-alkanes.The reaction of tetrahydrofuran with the less-reactive hydrogen chloride stops at the chlorohydrin stage, whereas the reaction in the presence of zinc chloride catalyst leads to the formation of the dichloride. The crude reaction mixture containing the intermediate chlorohydrin may be treated directly with phosphorus tribromide, yielding tetramethylene chlorobromide. The preparation of dibromides can be accomplished easily with hydrogen bromide or phosphorus and bromine and diiodides, by the action of potassium iodide and orthophosphoric acid. ... 

Acylation and alkylation of aromatic compounds. Benzophenones are obtained in good yield when a mixture of a phenolic ether and an alkoxybenzoic acid is treated with PPA prepared by stirring a mixture of 8 parts by weight of P2O5 and 5 parts by volume of 90% orthophosphoric acid (dl. 75) at 85° for 30 min. (Ayers and Denney ). Thus veratrole and vanillic acid afforded4-hydroxy-3,3, 4 -trimethoxybenzophenone. 

Stone and Shechter have developed high-yield procedures for the preparation of alkyl iodides from alcohols, ethers, and olefins by reaction with a reagent described as 95% orthophosphoric acid in combination with potassium iodide. For the conversion of 1,6-hexanediol into 1,6-diiodohexane, a mixture of 65 g. of P2O5 and 231 g. (135 ml.) of 85% phosphoric acid is stirred mechanically and let cool to room temperature, potassium iodide and 1,6-hexanediol are added, and the mixture is stirred and heated as indicated. The initially homogeneous solution separates into... 

Trihydroxyacetophenone in xylene containing orthophosphoric acid was treated with buta-1,3-diene at 30-5°C during 2 hours and stirring continued for a further 15 hours to give the alkylated product 5-(but-2-enyl)-2,3,4-tri-hydroxyacetophenone and a small quantity of the final cyclised product... 

The alkylation of benzene by propan-l-ol and AICI3 in hexane or cyclohexane has been studied over the temperature range -40 to -f-100°C by n.m.r. spectroscopy. Structures of the several products of alkylation of mesitylene with 3,5-di-t-butyl-4-hydroxybenzyl alcohol and of resorcinol and its methyl ethers with a-butylbenzyl alcohol plus orthophosphoric acid have been elucidated. Allylation of guaiacol by allyl alcohol and an acid catalyst is... 

Orthophosphoric acid esters, alkylation with - 22, 775 Orthosilicates s. Silicates Osmic acid s. Osmium tetroxide Osmium tetroxide OCv >CC Oxa... s. a. 0-Heterocyclics Oxacyclimmonium salts, 2-hydroxy- 22, 990, 3,5-Oxadiazines, 6-oxo-... 

The heat of hydrolysis with water is 74-7 Cals.2 If much water is used the products are orthophosphoric and hydrochloric acids, but when the compound deliquesces in moist air pyrophosphoryl and metaphosphoryl chlorides [q.v.) are formed as intermediate products.3 It is also hydrolysed by hydroxylated organic compounds and is much used for preparing chlorinated derivatives, e.g. C2H5C1 and CH3COCl from C2H5OH and CH3COONa respectively. By this means also alkyl chlorophosphates and alkyl phosphates can be prepared, e.g. —... 

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