Wiley InterScience Backfile Collection 1832-2000
Chemistry and Pharmacology
α-Substituted Phosphonates. XXXI. The Reaction of N,N,N′,N′-Tetramethyl Chloroformamidinium Chloride with P(III) CompoundsN,N,N′,N′-Tetramethyl chloroformamidiniumchloride (4) does not react with triethyl phosphite (TEP) or isopropyl diphenylphosphinate to give the expected bisphosphoryl derivatives 7 and 11, respectively, but primarily the monophosphorylated amidinium salts 6 and 10 respectively. The phosphine oxide 10 is stable, while 6 undergoes an elimination of ethyl chloride to the betain 8. Even under more drastic conditions the reaction of 4 or 8 with TEP does not lead to the expected bis(dimethylamino)bisphosphonate 7, but to the monoaminated bisphosphonate 1, involving a reduction step. Similar reduction has been observed under mild conditions in Michaelis-Arbusov reaction of dichloromethylenimonium chloride, yielding the expected trisphosphonate 2 and the bisphosphonate 1 as a by-product.
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