Acetone → 2-(N-isopropylamino)-4-methylbenzophenone

Participants

Reaction Conditions

Reaction Steps

To a solution of 63.3 gms. of 2-amino-4-methylbenzophenone in 722 mls. of acetone is added 87 gms. of 49% aqueous sulfuric acid. The mixture is cooled to 20° C. With stirring, and by portionwise addition, 31.2 gms. of sodium borohydride is added to the mixture over a period of 70 minutes. After the addition, the mixture is stirred for an additional 5 hours at 25° C. The suspended solids are filtered and then washed with 300 mls. of acetone. The acetone solutions are combined and concentrated. To the concentrate is added 200 mls. of heptane and 60 mls. of 4N ammonium hydroxide. The liquid layers are separated, then the heptane phase is washed with 20 mls. of water, extracted twice with 20 mls. of 2N sulfuric acid each time, and then washed to neutrality with water. The heptane phase is then dried over magnesiun sulphate, filtered, and concentrated under vacuum to a constant weight of 74.5 gms. or crude yield of 98%, which is shown by analysis to constitute an actual yield of about 95% of the desired 2-(N-isopropylamino)-4-methylbenzophenone.

Provenance & Evidence