反应详情

A solution of 0.69 g (2 mmol) of tetraethyl 4-aminobutane-1,1-bisphosphonate (according to DE 3,225,469 A1, 01.05.1984) and 0.402 g (2 mmol) of 3,5-dimethylpyrazole-1-carboxamidine nitrate in 10 ml of DMF is heated at boiling point for 3 hours. The DMF is then distilled off in vacuo and the residue is dissolved in a little water. After extraction with diethyl ether and ethyl acetate (the organic extracts are discarded), the aqueous phase is distilled in vacuo. A dark oil (0.89 g) remains. This is heated at boiling point for 8 hours in 15 ml of concentrated hydrochloric acid. The excess hydrochloric acid is distilled off and the residue is treated with a little water, DMF and acetone. The precipitate is filtered off with suction and dried in vacuo.

1. customfor 3 hours
2. distillationThe DMF is then distilled off in vacuo
3. dissolutionthe residue is dissolved in a little water
4. extractionAfter extraction with diethyl ether and ethyl acetate (the organic extracts
5. distillationis distilled in vacuo
6. temperatureThis is heated
7. customfor 8 hours
8. distillationThe excess hydrochloric acid is distilled off
9. additionthe residue is treated with a little water, DMF and acetone
10. filtrationThe precipitate is filtered off with suction
11. customdried in vacuo