1,2-Dichloroethane → HCID 86732534, compound

Participants

Reaction Steps

Sodium triacetoxy borohydride (5.41 g) and acetic acid (2.19 mL) were added to a mixture of a mixture (3.45 g) of benzyl 5-oxo-4,5,6,7-tetrahydro-2H-indazole-2-carboxylate and a regioisomer thereof, cyclopropylamine (0.878 mL), and 1,2-dichloroethane (70 mL) under an argon gas atmosphere, followed by stirring for 18 hours at room temperature. Water was added to the reaction liquid, followed by stirring for 2 hours at room temperature, and then pH thereof was adjusted to 8 by using saturated aqueous bicarbonate, followed by liquid separation. The organic layer was dried and then concentrated under reduced pressure. A dioxane solution (4.15 mL) of 4 M hydrogen chloride was added to a mixture of the residue and ethyl acetate (100 mL), followed by stirring for an hour at room temperature. The precipitate was collected by filtration and washed with ethyl acetate, thereby obtaining a mixture (3.26 g) of benzyl 5-(cyclopropylamino)-4,5,6,7-tetrahydro-2H-indazole-2-carboxylate monohydrochloride and a regioisomer thereof.

Provenance & Evidence