Phosphite dibenzyl hydrogen

From phosphorus trichloride, benzyl alcohol and 2 mol. of a tertiary base, dibenzyl hydrogen phosphite (XIV), is obtained which on treatment with chlorine or a chlorinating agent (e.g. sulphuryl chloride)4 gives the phosphorochloridate (XV). Although not isolated, (XV) is almost certainly obtained by treatment of (XIV) with a polyhalogen hydrocarbon because reaction in the presence of an alcohol or of a primary or secondary amine gives a triester (XVI) or a phosphoramidate. 

Synthesis of Phosphoric Acids and their Derivatives.-New approaches to the preparation of dialkyl phosphorofluoridates include the treatment of a vinyl phosphate, e.g.,(l), or an irninophosphace, e.g.,(2), with triethylamine tris(hydrogen fluoride) when the alkyl group consists of a suitably protected nucleoside, the reaction between mono(crimethylsilyl) phosphite in pyridine and sulphuryl chloride fluoride at -30° has been successfully explored. Dibenzyl phosphorofluorldate, hitherto unreported, has been obtained from tecrabenzyl diphosphate and caesium fluoride, and also from the reaction between dibenzyl hydrogen phosphate and 2-fluoro-N-methylpyridinlum tosylate. ... 

An ethereal soln. of phenyldiazomethane added gradually during 20 min. to an ice-cold stirred ethereal soln. of phosphorous acid — dibenzyl phosphite. Y 84%.—An ethereal soln. of diphenyl-diazomethane added to a suspension of dibenzyl hydrogen phosphate until a pink coloration persists, then more dibenzyl hydrogen phosphate added until the coloration disappears —benzhydryl dibenzyl phosphate. Y almost 100 %.—This method is limited by the accessibility of the diazo compounds. (F. e. s. F. R. Atherton, H. T. Howard, and A. R. Todd, Soc. 1948, 1106.)... 

The parent phenylphosphoramidic acid, PO(NHPh)(OH)2, was obtained by a method which consisted in the ready hydro-gmolysis of dibenzyl phenylphosphoramidate. An attempt to prepare dibenzyl p-dimethylaminophenylphosphoramidate by the action of AA -dimethyl-p-phenylenediamine on dibenzyl jhosphorochloridate gave only an oil. When, however, a mixture of the amine, dibenzyl hydrogen phosphite, and trichloro-Ixomomethanewas used, a good yield of thedibenzylp-dimethyl-aminophenylphosphoramidate was obtained. It is a crystalline solid which causes severe dermatitis the irritation develops slowly and with some individuals persists for weeks. 

Thus, as shown below [Scheme 6], exposure of lactol 14 to dibenzyl-A,lV-diethylphosphoramidite and l//-tetrazole in dichloromethane followed by oxidation of the intermediate phosphite with 30% hydrogen peroxide provided the desired a-phosphate 11 (3Jhih2 = 3.4 Hz) in 86% yield as a single diastereomer. The stage was now set for introduction of the pentapeptide side chain. 

Allyl phosphorodichloridite. 1169 Bis(trimethyIsilyl) phosphonite, 2611 0-0-tert-Butyl diphenyl monoperoxophosphate, 3712 0-0-tert-Butyl di(4-tolyl) monoperoxophosphate, 3763 Diallyl phosphite (Di-2-propenyl phosphonite), 2456 Dibenzyl phosphite, 3658 Dibenzyl phosphorochloridate, 3650 Di(( -( -teri-butyl) ethyl diperoxophosphate, 3374 Dibutyl hydrogen phosphite, 3086 Diethyl ethanephosphonite, 2572 Diethyl 4-nitrophenyl phosphate, 3329 Diethyl 4-nitrophenyl thionophosphate, 3328 Diethyl phosphite, 1733... 

Dibenzyl Phosphite. Pbosphonic acid bhiphenyt-methyl) ester dihenzyl hydrogen phosphiie benzyl phosphite. C,4Hl503P mol wt 262,24. C 64,12%, H 5-77%, O 18,30%, P 11.81%, (HO)P(OCH2C4Hs)2- Prepd by adding drop wise a mixrure of dimethylan time and benzyl ale to a SOln Of phosphorus trichloride in benzene Atherton et a/, J, Chem- Soc, 1945, 382 U.S. pat. 2,490 573 <1949 to Hoffmann La Roche). 

Many communications have concentrated on specific amino phosphonic acids or derivative types. Thus, esters of phosphonoaminoacetic add were obtained by the reactions between trialkyl (ethyl) phosphite and (218) and which are thought to proceed via the phosphorane (219). A sequence has been presented for the preparation of the mono- and di-benzyl esters of N-chz protected (a-aminoben-zyl)phosphonic acid. A synthesis of (aminomethylene)bisphosphonic acid from dibenzylamine, dibenzyl hydrogenphosphonate and triethyl orthoformate has been noted and the asymmetric hydrogenation of (220) in the presence of chiral phosphine catalysts yields samples of (221) with e.e.s of 63-96%. The pyrrolidine-based compound (222) has been prepared from methyl S)-N-methoxycarbonyl-4-oxo-2-pyrrolidinecarboxylate and iV-coupled 4-amino-butanal diethyl acetals were the starting materials in syntheses of the pyrrolidine-2-phosphonic add derivatives (223) in which Z represents the iV-protected amino add or peptide moiety. ... 

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