Dimethyl 4- phenylphosphonate

Through the photolytic extrusion of dimethyl phenylphosphonate from oxazaphos-phoranes, the corresponding carbazoles are formed by a phosphorus analogue of the Graebe-Ullmann reaction. The irradiation of 2,2-dimethoxy-3-(4-methoxyphenyl)-2-phenyl-2,3-dihydrobenz-l,3,2-oxazaphospholine (22) in benzene gives 3-methoxycar-... 

NMR has been used to study ligand exchange in non-coordinating solvents for a series of Be(C104)2-4L (L = trimethyl phosphate, DMSO, DMA, DMF, NMA, 1,1,3,3-tetramethylurea, dimethyl methylphosphonate and dimethyl phenylphosphonate) complexes. 3H NMR studies show that the mode of activation for exchange on beryllium varies from dissociative to associative depending upon L and the nature of the non-coordinating solvent.127 128... 

Tosylhydrazones can also undergo additions of pentavalent phosphorus derivatives, such as alkyl phenylphosphinate [Ph(H)P(0)OR] dimethyl phosphonate [HP(0)(OMe)2], or dimethyl phenylphosphonate [PhP(0)(0Me)2], to introduce phosphorus atoms. 

For example, compound 196 reacts with dimethyl phenylphosphonate to afford the adduct 197 and reductive removal of the tosylhydrazino group by NaBH4 leads to the phosphi-... 

A detailed study of the interaction of dimethyl phenylphosphonite (62 R = Ph) and ( )-63 (R = Pr ) initially showed that, at -50 °C only traces of unsaturated phosphinate and dimethyl phenylphosphonate are formed, and that the phosphorane 66 (R = Ph, R = Pr ) is the main produc In outline, the system of observed reactions resembles that observed for trimethyl phosphite, with the formation of the dipolar species 65 in equilibrium with the phosphorane 66 and with the ylide 67 the last acts as the immediate precursor to the methyl [(alk-2-enyl)phenyl]phosphinates 68 (R = Ph). Although hydrolysis of the phosphorane could be expected to yield the methyl [(nitroalkyl)phenyl]phosphinates... 

The phosphoryl group evidently, and not surprisingly, deactivates an attached benzene ring during electrophilic substitution reactions the sulphonation (with SO3) of phenylphosphonic acid leads initially to the 3-sulphonic acid, and subsequently at 180-240 °C to the 3,5-disulphonic acid. The nitrations of (4-chlorophenyl- or (4-bro-mophenyl)-phosphonic acids have given products described as the 3-nitro derivatives, but it has also been stated that the nitration of dimethyl phenylphosphonate gives dimethyl (4-nitrophenyl)phosphonate, a pattern of substitution certainly observed in the nitration of... 

N -butylphosphonic acid, phenylphosphonic acid, ethyl methylphosphonic acid, ethyl methylthiophosphonic acid, isopropyl methylphosphonic acid, pinacolyl methylphosphonic acid, dimethyl phenylphosphonate in 16 min Methylphosphonic acid, ethylphosphonic acid, CZE... 

Dichloropyrazines have also been prepared from the corresponding hydroxy compounds as follows 2,3-dihydroxypyrazine with phosphoryl chloride containing pyridine (481, 757) [see Schneller and May (828) re the use of phenylphosphonic dichloride at 150-170°] 2,3-dihydroxypyrazine and its methyl, dimethyl, phenyl, diphenyl, and 5-methy 1-6-phenyl derivatives with phosphoryl chloride (483, 829) [N.B. error in work of Minovici and Bente (830)] 2-chloro-5-hydroxypyrazine with phosphoryl chloride (831) 2-chloro-6-hydroxypyrazine with phosphoryl chloride at reflux for 6hours (832) and 2,5-dihydroxy-3-phenylpyrazine and3,5-dihydroxy-2-phenylpyrazine with phosphoryl chloride at 180-200° (829). 

Competitive displacement of the HeO and HeS ligands from Q,S-dimethyl phenylphosphonothioate, when the latter is treated with NaOEt in EtOH, results in the formation of Q-ethyl S-m thyl phenylphosphonothioate (246) and preferentially, Q-ethyl Q-methyl phenylphosphonate (247), both with inversion of configuration each displacement is accompanied by racemization resulting from simultaneous and competitive displacement of EtO groups. Further displacements by EtO lead, in each case, to diethyl... 

These heteropoly salts are all white solids with similar IR spectra and well-resolved medium to strong peaks at 1130-970 cm " (P—O stretch) and 950-890 and 730-660cm (M—O terminal and bridging stretches). The ammonium and tetramethylammonium (sodium double) salts are soluble in water tributylammonium pentatungstobis(phenylphosphonate) is insoluble in water and methanol but soluble in acetonitrile, /V./V-dimethylformamide, dimethyl sulfoxide, and dichloromethane. Proton NMR spectra of the... 

More recently, Souzy et al. synthesized a fluorinated vinyl ether-containing phosphonate moiety, i.e. dimethyl 4-[(a,p,p-trifluorovinyl)o gr]-phenylphosphonate, from a Michaelis-Arhuzov reaction in the presence of nickel(II) chloride as Lewis acid at 110 °C. Nevertheless, the reaction yield remains low (Scheme 3.6). 

Scheme 3.6 S mthesis of dimethyl 4-[(a,P,P-trifluorovinyl)o3gr]phenylphosphonate.

EMPA, IMPA, PMPA, MPA CE with EOE reversor (didodecyl dimethyl-ammonium hydroxide) Indirect UV detection at 214 nm (1 mM phenylphosphonic acid as ultraviolet visualization agent) 100 uM 5 30... 

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