1,2-Dibromo-3,4-dimethylbenzene → Indan-2,2-diphosphonic acid

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Reaction Steps

Using the procedure described in Example I, tetraisopropylmethanediphosphonate MDP was converted to the desired ester in 70% yield by reaction with dibromo-o-xylene at 80° C. for 3 h: mp 55°-57° C.; 1H NMR (CDCl3) 7.15 (s, 4H, aromatic), 5.00-4.55 (m, 4H, CH), 3.60 (t, 4H, J=17.6 Hz, CH2), 1.26 (t, 24H, J=6 Hz, CH3); 31P NMR (CDCl3) 24.7 ppm; Cl mass spectrum m/e 447 (MH+). Anal. calcd for C21H36O6P2 : C, 56.49; H, 8.13; P, 13.88. Found: C, 56.71; H, 8.24; P, 14.18.

Provenance & Evidence