N,N-Diethylaniline → 3-bromo-2-(4-chlorophenyl)-4,5,6,7-tetrahydro-2H-indazole

Participants

Reaction Steps

To 5.0 parts of 2-(4-chlorophenyl)-1,2,4,5,6,7-hexahydro-3H-indazol-3-one [from Example 1(c)] with 3.0 parts of N,N-diethylaniline and 5.0 parts of dimethylformamide under nitrogen atmosphere was added 6.3 parts of phosphorous oxybromide. The mixture was heated to 130°-170° for 2 hours. After cooling to room temperature, the reaction mixture was extracted with 100 parts of diethyl ether, washed with water, dried over anhydrous magnesium sulfate and concentrated on a rotary evaporator. Recrystallization from methanol/water gave 2.7 parts of product, m.p. 101°-102°.

Provenance & Evidence