反应详情

To a solution of 3-[2-(2-tert-butoxycarbonylmethyl-1-cyclohexenyl)-3-oxo-2,3-dihydropyridazin-6-yl]-2-phenylpyrazolo[1,5-a]pyridine (248 g) in dichloromethane (500 ml) was added dropwise trifluoroacetic acid (396 ml) at 5° C. After addition, a reaction mixture was allowed to warm to ambient temperature, and stirred for 20 hours. Solvent was removed by distillation and toluene azeotrope (500 ml×2). A residue was dissolved in a mixture of 1N-aqueous sodium hydroxide solution (3.5 l) and water (0.5 l), which was washed with ethyl acetate (600 ml). Aqueous layer was added dichloromethane (2 l) and the pH was adjusted to pH 3.5 with 2N-aqueous hydrochloric acid. Organic layer was separated and aqueous layer was reextracted with dichloromethane (1 l). Organic layer was combined, which was washed with water (1 l×2) and dried over magnesium sulfate. Evaporation of the solvent gave a crude solid, which was recrystallized from 85% aqueous ethanol (1.25 l) and collected by filtration to give 3-[2-(2-carboxymethyl-1-cyclohexenyl)-3-oxo-2,3-dihydropyridazin-6-yl]-2-phenylpyrazolo[1,5-a]pyridine (152.2 g). Mother liquor was concentrated to give crude solid, which was recrystallized in the similar manner to give the second crystal of the object compound (27.63 g).

1. additionAfter addition
2. customSolvent was removed by distillation and toluene
3. dissolutionA residue was dissolved in a mixture of 1N-aqueous sodium hydroxide solution (3.5 l) and water (0.5 l), which
4. washwas washed with ethyl acetate (600 ml)
5. additionAqueous layer was added dichloromethane (2 l)
6. customOrganic layer was separated
7. washwhich was washed with water (1 l×2)
8. dry with materialdried over magnesium sulfate
9. customEvaporation of the solvent
10. customgave a crude solid, which
11. customwas recrystallized from 85% aqueous ethanol (1.25 l)
12. filtrationcollected by filtration