Tetraethyl methylenediphosphonate → Tetraethyl 2-(1,2,5-thiadiazol-4-yl)-ethane-1,1-diphosphonate

Beteiligte Stoffe

Reaktionsschritte

A solution of 1.62 g. tetraethyl methanediphosphonate in 10 ml. anhydrous toluene is added dropwise to 0.2 g. sodium hydride (69%) in 10 ml. anhydrous toluene. After termination of the evolution of hydrogen, 1 g. 4-bromomethyl-1,2,5-thiadiazole in 10 ml. anhydrous toluene is added thereto and the reaction mixture stirred for 12 hours at ambient temperature. A little water is then added and the organic phase is separated off, dried and evaporated. The residue is purified over a column of silica gel (100 g.; elution agent methylene chloride/methanol 98:2 v/v). There is thus obtained 1.18 g. of the desired product in the form of a colourless oil; yield 55% of theory.

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