Phosphorus trichloride → Minodronic acid

Imidazo[1,2-a]pyridin-3-yl acetic acid (46 gm), phosphorous acid (75 gm) and 1,4-Dioxane (900 mL) was taken in a four necked round bottom flask fitted with an addition funnel, mechanical stirrer, condenser and thermometer pocket and allowed to stir at 90-95° C. Phosphorus trichloride (130 gm) was then added to reaction mixture and allowed to heat at 90-95° C. The reaction mixture was cooled and distilled water (450 mL) was added to it. The reaction mixture was further heated to 90-95° C. It was then cooled and acetone (1400 mL) was added to it. The solution was further cooled to 0-5° C. and stirred for 4-5 hrs. The precipitated solid was filtered and dried under vacuum to give 44 gm of product.

1. customfitted with an addition funnel, mechanical stirrer, condenser
2. temperatureto heat at 90-95° C
3. temperatureThe reaction mixture was cooled
4. distillationdistilled water (450 mL)
5. additionwas added to it
6. temperatureThe reaction mixture was further heated to 90-95° C
7. temperatureIt was then cooled
8. additionacetone (1400 mL) was added to it
9. temperatureThe solution was further cooled to 0-5° C.
10. stirringstirred for 4-5 hrs
11. filtrationThe precipitated solid was filtered
12. customdried under vacuum

ORD record

ord-244888b077e44a39b46afb91d4ce1f4d

Source dataset

uspto-grants-2011_01

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07872144B2