Trimethyl phosphate, methylation

Methyl-3-phenyl-5-(3-trifluoromethylphenyl)-4-pyridone. See l-Methyl-O-phenyl-S-fO-ltrifluoromethyl) phenyl]-4(1H)-pyridinone Methyl phosphate. See trimethyl phosphate Methyl phosphite. See Trimethyl phosphite Methyl phosphonate. See Dimethyl hydrogen phosphite... 

The above is a general procedure for preparing trialkyl orthophosphates. Similar yields are obtained for trimethyl phosphate, b.p. 62°/5 mm. triethyl phosphate, b.p. 75-5°/5 mm. tri-n-propyl phosphate, b.p. 107-5°/5 mm. tri-Mo-propyl phosphate, b.p. 83-5°/5 mm. tri-wo-butyl phosphate, b.p. 117°/5-5 mm. and tri- -amyl phosphate, b.p. 167-5°/5 mm. The alkyl phosphates are excellent alkylating agents for primary aromatic amines (see Section IV,41) they can also be ua for alkylating phenols (compare Sections IV,104-105). Trimethyl phosphate also finds application as a methylating agent for aliphatie alcohols (compare Section 111,58). 

Bromo-Ar,Ar-dimethyl-3-(trifluoromethyl)aniline has been prepared by the methylation of 4-bromo-3-(trifhioromethvl)aniline with trimethyl phosphate in 70-80% yield.3 The present method, which effectively uses 3-(trifluoroinethyl)aniline as starting material, offers advantages in cost, yield, and ease of purification. 

Stereochemistry. - There has been a far infra-red spectroscopic study of ethyl phosphine,130 and in combination with X-ray fluorescence, further work completed on the conformational analysis of dialkylphenyl phosphines.131 The influence of water on the conformational equilibria of trimethyl phosphate has received attention.132 There has been a low temperature solid state and matrix isolation study of methyl phosphorodichi oridate,133 and a conformational study of polymorphic modifications of diphenyl-phosphinyl acetic acid hydrazide. 34... 

Polar substituents have been attached to the porphyrin core in order to achieve water-solubility. (685) has been synthesized by reaction of the Ni11 complex of tetrakis(pentafluorophenyl)-porphyrin with dimethylammonium hydrochloride in DMF, followed by methylation with methyl trifluoromethanesulfonate (triflate) in trimethyl phosphate.1778 The triflate and chloride salts are... 

To [Co(en)2((S)-GluOBzl)]I2 (5.0 g, 7.3 X 10 3 mol) in dry trimethyl-phosphate (18 ml, 4A sieves) contained in a conical flask equipped with a drying tube was added methyl trifluoromethane sulfonate (8.0 g, 4.9 x 10 2 mol) and the mixture was stirred at room temperature for 30 min (Caution The alkylating agent is believed to be extremely toxic. Use a hood and avoid skin and vapor contact). The deep orange solution was then slowly poured into rapidly stirred dry ether (600 ml) and the precipitated semisolid recovered by decantation. The residue was dissolved in the minimum volume of dry methanol (10-20 ml), the product reprecipitated using further dry ether (400 ml), and the solid recovered as before. A further precipitation using methanol (10-20 ml) and dry ether (800 ml) produced the complex as a finely divided solid. This was recovered by filtration (porosity 4 sin-... 

It is now known1 that trialkyl phosphates will indeed alkylate phenols. The idea has been extended2 to the production of methyl ethers from alcohols and trimethyl phosphate, and of a butyl ether according to the equation... 

Ah initio calculations to map out the gas-phase activation free energy profiles of the reactions of trimethyl phosphate (TMP) (246) with three nucleophiles, HO, MeO and F have been carried out. The calculations revealed, inter alia, a novel activation free-energy pathway for HO attack on TMP in the gas phase in which initial addition at phosphorus is followed by pseudorotation and subsequent elimination with simultaneous intramolecular proton transfer. Ah initio calculations and continuum dielectric methods have been employed to map out the lowest activation free-energy profiles for the alkaline hydrolysis of a five-membered cyclic phosphate, methyl ethylene phosphate (247), its acyclic analogue, trimethyl phosphate (246), and its six-membered ring counterpart, methyl propylene phosphate (248). The rate-limiting step for the three reactions was found to be hydroxyl ion attack at the phosphorus atom of the triester. ... 

As in the acyclic series, it is possible to change the stereoselectivity of the methylation reaction by using other methylating agents. At 20 CC, the stereoselectivity observed with iodomethane is completely reversed with trimethyl phosphate. In contrast, in the presence of a large excess of lithium perchlorate, the stereochemistry observed with iodomethane is almost restored (Table 2)40... 

Harada et al. studied the TiO2 photocatalytic mineralization of trimethyl phosphate, trimethyl phosphite, and O, (9-dimethyl ammonium phosphodithioate and reported excellent mass balance based on phosphate, sulfate, and carbon dioxide produced after prolonged illumination [39]. Subsequent studies found the organophosphorus insecticides dimethyl-2,2-dichlorovinyl phosphate [Eq. (5)] and di-methyl-2,2,2-trichloro-I-hydroxyethyl phosphonate were mineralized by solar irradiation in the presence of suspended TiO2 [40] ... 

IV, 104-105). Trimethyl phosphate also finds application as a methylating agent for aliphatic alcohols (compare Section 111,58). 

The reaction of trimethyl phosphate, (MeO)3PO, with NiBr2 results in the neutral bis-dimethoxyphosphato complex by elimination of one methyl group from the neutral phosphoric esters (equation 185).1708 But when nickel halides are reacted at higher temperatures with the neutral diisopropylmethylphosphonate, an alkyl elimination and a phosphato condensation occur (equation 186).1709... 

The rapid aminolysis of cobalt(llI)-chelated glycine esters in aprotic solvents (Scheme 10 N4 = (en)2 or trien, R = Me, Et, R = H, CHR"C02Et) could be of value in peptide synthesis. The cobalt atom acts as both an N-protecting and an activating group. The synthesis of the chelated amino acid esters has presented some difficulties.207 A recent paper208 describes the use of methyl trifluoromethanesulfonate for the alkylation of chelated amino acids using dry trimethyl phosphate... 

Fig. 8 Why phosphate esters are inherently slower to add hydroxide than carboxylate esters despite a smaller thermodynamic barrier. The distortions in starting material and product are compared for methyl acetate and trimethyl phosphate. There are more angles distorted in the phosphate case, and the total angular distortion is greater for addition to phosphate. Reproduced with permission from ref.9...

To explore further the structural requirements for this unexpected nitrile formation (51 — 52) the reaction of the 1-methyl derivative 56 with sodium azide was examined. In this case the diazido derivative 57 was obtained instead of the nitrile 58. In a control experiment the nitrile 58 was also prepared by methylation of 52 with trimethyl phosphate in the presence of potassium carbonate. 58 reacted in analogy to 52 with sodium azide to furnish the tetrazole 59. Attempted decomposition of the geminal diazide 57 in refluxing DMF failed to give the tetrazole 59 (which is very surprising in view of the easy conversion of 38 to 39) [90LA505],... 

Given the good interpolation of the susceptibility spectra by the GGE distribution we can focus on the temperature dependence of the parameters. We compiled the results from analyzing DS spectra of several type A glass formers [6,136,137,142,230,273,275], Note that the glass formers trimethyl phosphate (TMP, [230,275]), 3-fluoro aniline (FAN, [142]) and methyl tetrahydrofuran (MTHF, [331]) show both the excess wing and a p-process (cf. Fig. 35). In this... 

Figure 30. Temperature dependence of the parameters P and y of the GGE distribution Eq. (36). (a) p and y are shown for the glass formers glycerol (GLY) and propylene carbonate (PC). In addition P/c (crosses) shows that i x y holds in good approximation. For clarity data sets of the Augsburg and Bayreuth group are not distinguished, (b) y (open symbols) and P/c (full symbols) for 2-picoline (2-PIC), trimethyl phosphate (TMP), propylene glycol (PG), 3-fluoro aniline (3-FAN), methyl tetrahydrofuran (MTHF), m-tricresyl phosphate (m-TCP) and ethylene glycol (EG) c = 3.0 0.5. Figures taken from Ref. [275],...

SYNS METHYL PHOSPHATE NCI-C03781 PHOSPHORIC ACID, TRIMETHYL ESTER TMP 0,0,0-TRIMETHYL PHOSPHATE... 

Delpuech et al. (106) examined the tetrahedral solvates of the beryllium cation with trimethyl phosphate (TMPA), dimethyl methyl phosphonate (DMMP), N,iV-dimethylamido-0,0 -dimethyl phosphate (DMADM P), bis-A,iV-dimethylamido-0-methyl phosphate (TMDAMP), and hexamethylphosphorotriamide (HMPT) by NMR including that of Be. The kinetics of ligand exchange ... 

Ending of names of anions and esters of inorganic oxoacids having the ic ending in the acid name, e.g. nitrate, phosphonate, trimethyl phosphate, and of anions and esters of organic acids, e.g. acetate, methyl acetate, thiocyanate. See Tables IR-8.1 and IR-8.2 and Table IX for more examples of ate anion names. See also inate , onate . 

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