Structure of the Reaction Products of Fully Esterified Phosphorus(III) Acids and α-Halo Carbonyl Compounds¹

The Chemistry and Properties of Enol Phosphates.

“…Ill could be converted to the trichloro derivative (IV) by further action of chlorine ( 261). The bromination of dialkyl vinyl phosphates took place under conditions similar to those above, yielding the dibromoalkyl esters as brown oils, which could rarely be distilled without considerable decomposition (19,157,286,310,327,328). In a few cases, however, halogenations were found to take an anomalous course, entirely independent of the normal halogen addition, yielding an alkyl halide, a halogen-containing carbonyl compound, and other products of unknown nature (19).…”

“…Diethyl vinyl phosphate (LXII) has been synthesized by the dehydrobromination of diethyl 2-bromoethyl phosphate (LXI) with sodium hydride in ether (19).…”

“…Treatment of LXI with sodium iert-butoxide in tertiary butyl alcohol also led to LXII, which, however, was contaminated with diethyl feri-butyl phosphate formed by the partial alcoholysis of LXII (19). The product obtained by the dehydrochlorination of diethyl 2-chloroethyl phosphate with ethanolic potassium hydroxide was considered to be the vinyl phosphate (LXII) (422,423).…”

“…Furthermore, the ease with which vinyl phosphates undergo alcoholysis in the presence of traces of alkali suggests that the product consisted mainly of triethyl phosphate. Later attempts to repeat this dehydrochlorination with ethanolic potassium hydroxide and other basic reagents were unsuccessful, yielding only ethanolysis and degradation products (19). This method seems to give better results when anhydrous sodium carbonate is used as the dehydrohalogenation agent at elevated temperatures-0,0-divinyl phenylphosphonate was obtained in a 62 per cent yield from 0,0-di-2-chloroethyl phenylphosphonate (423)or when the chloroform solution of the 2-haloalkyl phosphate is treated with aqueous sodium hydroxide, as shown by the isolation of dibutyl 2,2-dichlorovinyl phosphate from dibutyl 2,2,2-trichloroethyl phosphate in 50 per cent yield (327).…”

“…The compounds that have been prepared are listed in the addition of a little hydroquinone (19) has been found to enhance the reaction. The resulting dialkyl 1,2-dichloroalkyl phosphates were usually isolated by distillation (table 11), but with the higher alkyl analogs, distillation resulted in partial and sometimes complete decomposition to uncharacterized products or in the elimination of the elements of hydrochloric acid.…”