Benzoylphosphonates

Benzoic acid (271) when reacted with PCI3 yielded an adduct (272) which underwent an Arbuzov rearrangement to the phosphoryl compound (273), which eliminated 3HC1 to give benzoylphosphonic anhydride (274). Addition of water to the reaction mixture converted the anhydride (274) into benzoylphosphonic acid (275), which underwent... 

Diethyl benzoylphosphonate, C6H5C—P(OC2H5)2 (1). Mol. wt. 242.20, b.p. 141-147°/ 3 mm. The reagent is prepared by reaction of benzoyl chloride with triethyl phosphite... 

Benzoylation of alcohols.2 This reaction with 1 is markedly catalyzed by DBU, but not DMAP. Tertiary alcohols react slowly and it is possible to effect selective benzoylation of primary alcohols in the presence of secondary alcohols. The selectivity can be enhanced by use of diisopropyl benzoylphosphonate. 

Cool the reaction mixture and replace the condenser with a fractional distillation set up. Distil the product at vacuum-pump pressure, discarding any low boiling fore-run, and collect pure diethyl benzoylphosphonate, 14 (b.p. 141°C, 2.5 mmHg, 15.7 g, 67 %), as a yellowish liquid. 

In the presence of [PdMe2(PMePh2)3] diethyl benzoylphosphonate is degraded during minutes and with quantitative yield, into diethyl phenylphosphonate (l-oxoalkyl)phosphonic esters suffer a similar fate but the process may take several hours under the same conditions. When mixtures of aroylphosphonic diesters and esters of (l-oxoalkyl)phosphonic acids are brought into contact with the... 

A new method of cyclization has been developed, through the reaction of suitably or//ru-substituted diethyl benzoylphosphonates (41), or their acid chloride precursors, with trialkyl phosphites. An analogous reaction takes place with (42) to give the fluorenylphosphonate (43). The mechanism suggested involves initial attack on carbonyl oxygen, and gains support from the formation of the benzofuranylphosphon-ate (45) in the reaction of (44) with triethyl phosphite. 

The Reformatsky reaction of ethyl bromoacetate with dunethyl benzoylphosphonate takes place readily, but the yield of the expected linal product, ethyl benzoylacetate, is low (30%).52 ... 

Griffiths, D.V., Griffiths, P.A., Whitehead, B.J., and Tebby, J.C., Novel quasiphosphonium ylides from the reaction of trialkyl phosphites with dialkyl benzoylphosphonates. Evidence for carbene intermediates in the intramolecular cyclization of 2-substituted dialkyl benzoylphosphonates. 7. Chem. Soc., Perkin Trans. 1, 479, 1992. 

Ishmaeva, E.A., Zimin, M.G., Galeeva, R.M., and Pudovik, A.N., Dipole moments of organophosphorus compounds. Part 2. Benzoylphosphonates, benzoylphosphinates, and benzoylphosphine oxide. Izv. Akad. Nauk SSSR, Ser. Khim., 538, 1971 Bull. Acad. Sci. USSR, Div. Chem. Sci. (Engl. Transl.), 473, 1971. 

Pudovik, A.N., Gur yanova, I.V.. and Zimin. M.G.. Reaction of the monoethyl ester of ethylthiono-phosphinic acid with some substituted benzoylphosphonates, Zh. Obshch. Khim., 38, 1533, 1968 J. Gen. Chem. USSR (Engl. Transl.). 38. 1483. 1968. 

Griffiths, D.V., and Karim. K.. Studies of the reactions of 2-substituted dimethyl benzoylphosphonates with trimethyl phosphite. Phosphorus. Sulfur Silicon Relat. Elem., Ill, 107, 1996. 

Hydrolysis of diethyl benzoylphosphonate (84) proceeds by C—P cleavage in both phosphate and imidazole buffers. The rates in the two buffers are... 

General procedure for the preparation of dialkyl aroylphosphonates 279 The aroyl chloride (0.03 mole) is treated under nitrogen dropwise with the trialkyl phosphite (0.04 mole) at such a rate that the internal temperature does not exceed 35°. The resulting mixture is fractionated in a vacuum. As example, dimethyl benzoylphosphonate, b.p. 146°/2.5 mm, is obtained in 81 % yield from benzoyl chloride and trimethyl phosphite. 

The reactions of trialkyl phosphites with dialkyl benzoylphosphonates have also been extensively studied. At higher temperatures, novel ylidic phospho-nates (40) are produced via phosphite trapping of intermediate carbenes. Ylidic phosphonate (40 R = PhO) had characteristic NMR signals at 831 at 53.5 and at 31.6. The phosphate (41 R = PhO), was frequently observed in the reaction products and had a very characteristic P NMR spectnim with Saip at... 

---