ChemInform Abstract: Ethyl‐p‐nitrophenyl Esters of Halogenoalkanephosphonic Acids.

Abstract

Die Phosphonsäureesterchloride (I) reagieren mit Natrium‐p‐nitrophenolat (II) in Acetonitril zu den gemischten Phosphonsäureestern (III).

The Synthesis of Dialkyl α-Halogenated Methylphosphonates

“…47 However, the addition of a tertiary amine (pyridine 48,49 and triethylamine [50][51][52][53][54][55] ) remains the most widely used method to trap the hydrogen chloride. The direct addition of sodium alcoholate 56 is also a useful synthetic method. 66 The reaction of chloromethylphosphonyl dichloride with trialkylsilanol acetates yields organosilicon esters of chloromethylphosphonic acids.…”

“…Hemi-ethanolysis in the presence of triethylamine allows the synthesis of ethyl dichloromethyl chlorophosphonate (Cl(EtO)P(O)CHCl 2 ) and further alcoholysis with 4nitrophenol gives the mixed dichloromethylphosphonate diester in 57 % yield. 56 Reduction reaction : The chemical reduction of trichloromethylphosphonate via halogenmetal exchange with n-butyllithium followed by acidic hydrolysis gives diethyl dichloromethylphosphonate in moderate yield (55 %). 106 The yield was improved to 65 % by trapping the intermediate lithiodichloromethylphosphonate with trimethylsilyl chloride.…”

“…The nonvolatile liquid diethyl trifluoromethylphosphonate remained in the Pyrex tube in ~ 100 % yield. 122 or dichloride 56 in reaction with respectively isobutanol or ethanol gives the corresponding dialkyl trifluoromethylphosphonite ((R 1 O) 2 PCF 3 ) in 35 % yield (from the diiodo compound). 122 Oxidation with atmospheric air allows the formation of dialkyl trifluoromethylphosphonates (e.g.…”

“…ethyl) trifluoromethyl chlorophosphonate which after reaction with sodium 4-nitrophenolate or alcohol (methanol, ethanol, propanol, butanol) / triethylamine leads to the fully esterified trifluoromethylphosphonate in 41 to 59 % yield. 56,123 Dialkyl trifluoromethylphosphonite ((R 1 O) 2 P-CF 3 , R 1 = Et, i-Bu) can also react in a Perkow manner with chloral or with dichlorofluoronitrosomethane to give, in both cases, the expected mixed dialkyl trifluoromethylphosphonate with respectively 32-66 % 124 and 84-86 % 125 yields.…”

“…165 The alcoholysis of ethyl (trichloromethyl)chlorophosphonate with 4-nitrophenol yields 40 % of the mixed dialkyl trichloromethylphosphonate. 56 Oxidation reactions : Ethyl isopropyl methylphosphonate successively reacts with nbutyllithium and tetrachloromethane 33 to give the corresponding trichloromethylphosphonate in 21 % yield. In the same manner, ethylmethyl dichloromethylphosphonate gives 12 % yield of the trichloro compound.…”