反应详情

1.18 g. of the tetraethyl 2-(1,2,5-thiadiazol-4-yl)-ethane-1,1-diphosphonate described in Example 3 is mixed with 3.3 ml. trimethylbromosilane under an atmosphere of nitrogen. The reaction mixture is left to stand for 24 hours at ambient temperature and the solution is then evaporated, the residue is mixed with water, the solution is adjusted to a pH of 5 with sodium hydroxide and mixed with methanol. The precipitate obtained is filtered off with suction. There is thus obtained 0.56 g. (53% of theory)of the desired diphosphonic acid in the form of the disodium salt with 1 mole of water of crystallisation; m.p.>300° C.; Mrel =0.9.

1. additionis mixed with 3.3 ml
2. waitThe reaction mixture is left
3. customthe solution is then evaporated
4. additionthe residue is mixed with water
5. additionmixed with methanol
6. customThe precipitate obtained
7. filtrationis filtered off with suction