A convenient synthesis of diaryl methylphosphonates and transesterification products therefrom

Honig, Milton L.; Weil, Edward D.

doi:10.1021/jo00422a058

Cited by 8 publications

(3 citation statements)

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“…The synthesis of (I) is reported to proceed by the Arbuzov rearrangement of pentaerythritol dimethyldiphosphite, (II) (Mukmenev & Kamai, 1963;Friedman, 1964), the transester-i®cation of pentaerythritol, (III), with diphenyl methylphosphonate (Honig & Weil, 1977), and the reaction of methylphosphonic dichloride, (V), with pentaerythritol in dimethyl methylphosphonate, (IV) (Kiefer, 1983). The latter procedure gave high purity (I) in good yield, and was our method of choice.…”

Section: Commentmentioning

confidence: 99%

A pentaerythritol-derived spirodiphosphonate

2000

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The title spirodiphosphonate, 3,9-dimethyl-2,4,8,10-tetraoxa-3! 5 ,9! 5 -diphosphaspiro[5.5]undecane-3,9-dione, C 7 H 14 O 6 P 2 , a polymer additive, has crystallographic symmetry 2. At 100 K, its six-membered rings have chair conformations, with endocyclic torsion-angle magnitudes in the range 51.87 (8)± 58.93 (9) . The P O distance is 1.4749 (8) A Ê , while the PÐ C(methyl) distance is 1.7691 (12) A Ê .

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Section: Commentmentioning

confidence: 99%

A pentaerythritol-derived spirodiphosphonate

2000

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“…Compounds 2 have been fully characterised 7 by 1 H and 31 P NMR and spectral data of 2a,b,c,d were in accord with existing literature data. 8 When the reaction was run with 1b,c and a reagent ratio of 1:0.3:1, with the same sublimated AlCl 3 , methylphosphinates 3b,c and methyl phosphine oxides 4b,c, respectively, were also formed as major products in a total yield of about 60% besides small amounts of the expected 2b,c ( Table 1). In contrast, when the reaction was run on 1a,d,e the major product observed is always the corresponding methyl phosphonate 2a,d,e but in lower yield, and no appreciable amount of the related ring substituted products 3 and 4 is detected.…”

Section: Methodsmentioning

confidence: 96%

“…One involves the condensation of methylphosphonic dichloride with the appropriately substituted phenol. 13 The second procedure consists of reacting a triarylphosphite with methyl iodide alone 14 or in methanolic solution 8 for 3 h at 200-250°C. It should be noted that methylphosphonic dichloride is not readily available while in the second procedure the reaction temperature does not permit to obtain the corresponding p-halogen diaryl methylphosphonates in good yields.…”

Section: Methodsmentioning

confidence: 99%

New Feature of Friedel-Crafts Phosphonation of Anisoles: Unexpected In Situ Methylphosphorylation Reaction

Baccolini¹,

Boga²

1999

Synlett

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Anisoles 1, reacting with AlCl 3 and PCl 3 with appropriate reagent ratios, give, in good yields, the corresponding diaryl methylphosphonates 2 or the methylphoshinates 3b,c and the methylphosphine oxides 4b,c. This unexpected in situ methylphosphorylation explains the reported limited and conflicting results to obtain methoxy-substituted arylphosphonous dichloride with the same reagents. A suggested mechanism is also reported.Since the last century, the Friedel-Crafts-type reaction 1 using PCl 3 and AlCl 3 has been of interest for the direct phosphonation of an aromatic ring. However, this reaction is very sensitive to the type of substituents present on the aromatic ring. 2 In particular, very limited success and conflicting results have been reported when the reaction is carried out with anisoles. For example, anisole, 3,4 upon treatment with PCl 3 and AlCl 3 gave complex reaction mixtures depending on the quality of AlCl 3 with poor yields of methoxy-substituted arylphosphonous dichloride or phenylphosphorodichloridite and large amounts of undistillable residues:To increase the yield and the selectivity of this phosphonation reaction the use 4a of SnCl 4 and very recently the use 4c of BiCl 3 have been reported. In the past years we discovered 5 an unusual reaction of PCl 3 and AlCl 3 with thioanisoles which gave a new heterocyclic system (fused 1,2,3-benzothiadiphosphole) containing the P-PS 2 unit. Recently, the course of this unexpected diphosphonation reaction has been studied 6 and we have found that the reaction follows a complex multistep pathway which was a priori unpredictable and that the outcome of the reaction is very dependent on the ratio of the reagents and on the good quality of AlCl 3 (sublimated prior to use) which in this reaction is a true reagent and not a catalyst.Then, we thought to study again the reaction of anisoles 1 with AlCl 3 and PCl 3 , in order to find results which might explain the reported 3,4 formation of large amounts of undistillable residues. Several reactions were carried out with various molar proportions of reagents and different reaction conditions. The reaction of 1b with an appropriate ratio of the reagents, afforded a mixture containing as major products the corresponding diaryl methylphosphoryl derivatives 2b, 3b and 4b arising from an unexpected in situ methylphosphorylation (Scheme1). Scheme 1After several repeated attempts with small variations of reagent ratios and reaction conditions we could control the regiochemistry of this methylphosphorylation reaction in order to obtain mainly the diaryl methylphosphonates 2 (see Scheme 1). The best results were obtained with a 1: AlCl 3 : PCl 3 ratio of 1:0.6:1, at 70-80°C in atmosphere of dry nitrogen and without solvent (Table 1). In the case of 1c the reaction was complete in 7 h while in the other cases in about 10-15 h. A stoichiometric excess of PCl 3 was useful also to ease the stirring and the homogeneity of the reaction mixture. Compounds 2 have been fully characterised 7 by 1 H and 31 P NMR and spectral data...

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The Synthesis of Phosphonic and Phosphinic Acids and their Derivatives: Non‐Functionalized Acids

Edmundson¹

2009

Patai's Chemistry of Functional Groups

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Introduction The Formation of P  C ( sp 3 ) Bonds. Syntheses of Alkyl, Cycloalkyl and Aralkyl Phosphonic and Phosphinic Acids The Formation of P  C ( sp 2 ) Bonds. Syntheses of Alkenyl and Alkadienyl Phosphonic and Phosphinic Acids The Formation of P  C ( sp ) Bonds. Syntheses of Alkynyl Phosphonic and Phosphinic Acids The Formation of P  C (Aromatic) Bonds. Syntheses of Aryl Phosphonic and Phosphinic Acids Syntheses of Phosphonic and Phosphinic Acids by Modification Procedures

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A convenient synthesis of diaryl methylphosphonates and transesterification products therefrom

Cited by 8 publications

References 2 publications

A pentaerythritol-derived spirodiphosphonate

A pentaerythritol-derived spirodiphosphonate

New Feature of Friedel-Crafts Phosphonation of Anisoles: Unexpected In Situ Methylphosphorylation Reaction

The Synthesis of Phosphonic and Phosphinic Acids and their Derivatives: Non‐Functionalized Acids

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