Phenyl phosphorodichloridate

The reaction between benzoylhydrazine and ethyl or phenyl phosphorodichloridate yields 5-(2-benzoylhydrazino)-5,6-dihydro-2,8-diphenyl-4i7-l,3,4,6,7,5-oxatetra-azaphosphocine 5-oxide (32).87... 

Mol. wt. 298.64, m.p. 129-130°. The reagent is prepared by reaction of phenyl phosphorodichloridate with aniline in benzene. 

Phenyl phosphorodichloridate in DMSO, which participates chemically, converts benzylic amines into carbonyl compounds,... 

Phenyl phosphorodichloridate is regarded as the reagent most widely used for (he preparation of symmetrical dialkyl phosphates. ... 

A remarkable demonstration of the ease of formation of six-co-ordinate species from four-co-ordinate precursors is the observation that both phenyl phosphorodichloridate and the cyclic ester (33) give the salt (34) when treated... 

Chambers and Khorana treated phenyl phosphorodichloridate (89) with 2, 3 -di-0-acetyladenosine (89a), to form the 5 -phenyl phosphoro-... 

D-glucopyranosyladenine with phenyl phosphorodichloridate (89) (see p. 337) yielded 9-/8-D-glucopyranosyladenine 4 6 -cyclic phosphate. The 2 4 -, 3 6 -, and 4 6 -cyclic phosphates of l-/3-D-glucopyranosyl-uracil have also been reported. ... 

Phenyl phosphorodichloridate added to a mixture of 2-methyl-2-nonyl-l,3-dithiolane and Nal in acetonitrile under an atmosphere of argon, after a few min ca. 1 eq. DMF added, and stirred for 5 h at room temp, in the dark 2-undecanone. Y 94%. The method is generally applicable to aliphatic, aromatic and allylic mercaptals. F.e. and with POCI3 in place of PhOPOCl2 s. H.-J. Liu, V. Wiszniewski, Tetrahedron Letters 29, 5471 (1988). 

Phenyl phosphorodichloridate (s.a. Dimethyl sulfoxide/phenyl phosphorodichloridate)... 

Phenyl phosphorodichloridate 2-Chlorothioethers from ethylene derivs. 

A soln. of 10 eqs. DMSO in CH2CI2 treated with 5 eqs. phenyl phosphorodichloridate at —20° under argon, after 5 min 1 eq. 1-octadecene introduced, stirred at the same temp, for a further 5 min, allowed to warm to room temp., and water added after 1 h product. Y 79%. Regioselectivity is the reverse of that observed with sulfenyl chlorides /m 5-addition, however, is the same. F.e. and with POCI3 s. H.-J. Liu, J.M. Nyangulu, Tetrahedron Letters 29, 5467-70 (1988). 

I, 2-0-Isopropylidene-a-D-xylo- and -ribo-furanose each gave the two possible isomers of the corresponding cyclic 3,5-(phenyl phosphate) when treated with phenyl phosphorodichloridate, but only one isomer was formed on phosphorylation of the former compound with bis-(2,2,2-trichloroethyl) phosphorochlori-date. The synthesis of a new type of branched-chain sugar phosphate, trans-3-C-cyanomethylene-3-deoxy-l,2-0-isopropylidene-a-D-erythro-pentofuranose 5-[bis-(2,2,2-trichloroethyl) phosphate], was also reported. 2,3,4,6-Tetra-0-acetyl(or benzoyl)-P-D-glucopyranose reacted with tris(dimethylamino)phosphine and carbon tetrachloride to give both anomeric oxyphosphonium chlorides (see Vol. 9, p. 48), which afforded 1,2-orthoesters with alcohols or a mixture of phenyl 1-thio-D-glucopyranosides with thiophenol. Similar treatment of 2,3,4,6-tetra-... 

Phenyl phosphorodichloridate 163) is useful in the synthesis of asymmetric phosphate diesters such as that of the phosphatide shown below. 

Compounds possessing the cyclic phosphate structure may be prepared by the action of phosphorus oxychloride or phenyl phosphorodichloridate on a glycol, or by treating phosphate monoesters with trifluoroacetic anhydride (173) or a carbodiimide reagent (f74). The latter is the preferred reagent since it may be used in the presence of water and usually gives a good yield of a pure product. The reaction is formulated as follows ... 

The cyclic product is extremely sensitive to moisture (hydrolysis) and was more readily isolated as the cyclic diester. An interesting correlation has been observed the phenyl triesters of high energy cyclic phosphates (cyclic nucleotides, ethylene phosphate) are very reactive species, susceptible to decomposition. On the other hand, the phenyl triesters of low energy cyclic phosphates are stable, crystalline compounds. Hence, for example, the phenyl triester of trimethylene phosphoric acid is a crystalline compound readily prepared in high yield by reaction of 1,3-propanediol with phenyl phosphorodichloridate. 

Similarly, reaction of 321 with cyanoacetic ester and potassium carlxtnate gave the benzopyrane 322. When ketone 321 was treated with monoethyl malonate, triethylamine and phenyl phosphorodichloridate, the required coumarin 323a was obtained and subsequent alkaline hydrolysis gave the acid 323b [179] (Scheme 103). 

Several other compounds are formed in the reaction such as diesters (R0)2P02H, triesters (RO)3PO and cyclic esters. In order to avoid these side reactions, substituted compounds are now used, particularly diphenyl phosphorochloridate [(CjH50)2POCl], dibenzyl phosphorochloridate [(CfiH.CHiOliPOCllformonoesters, and phenyl phosphorodichloridate (C6HjO-POCl2) for diesters. 

Preparative Methods this reagent was first prepared in 81 % yield by reaction of 4 equiv of imidazole with 1 equiv of phenyl phosphorodichloridate in benzene at 60 °C5 The use of 2 equiv of imidazole and 2 equiv of triethylamine as base has been reported to give a yield of 98% of (1) (eq 1). ... 

Reagent (1) is superior in terms of yield to a variety of phospho-rochloridates, including Phosphorus Oxychloride. For example, in the case of 2-pyridyl aldoxime, with (1) a yield of 52% was obtained, whereas with phosphorus oxychloride the yield was 33% and with phenyl phosphorodichloridate the yield was 47%. The reaction is thought to proceed via an intermediate formed by O-phosphorylation of the aldoxime. The use of spin-labeled versions of (1) has been explored, in which the phenyl is replaced with the 2,2,6,6-tetramethylpiperidyl A -oxide group. ... 

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