Hydrochloric Acid → ethyl 4-[5-[3-methoxy-4-[N,N-bis(1-methylethyl)aminocarbonyl]phenoxy]pentoxy]benzenecarboximidoate monohydrochloride

Participants

Reaction Conditions

Reaction Steps

Ethanol (2B,6.0 L) is cooled in an ice bath to 0° C. and saturated with anhydrous hydrogen chloride over a period of 71/2 hours. The solution is left in the ice bath overnight and the hydrogen chloride addition is continued an additional hour at 0° C. 4-[5-(4-Cyanophenoxy)pentoxy]-3-methoxy-N,N-bis(1-methylethyl)-benzamide (4200 g, 9.57 mole) is added rapidly over 30 minutes and an exotherm raises the reaction mixture temperature to 10° C. Hydrogen chloride addition is continued for 6 hours and the purple solution stirred overnight at 20° C. The reaction mixture is followed by TLC (ethyl acetate/hexane, 2:1) using silica plates. A total of 4-5 days is required for completion of this reaction with periodic resaturation with hydrogen chloride. The thick purple solution is transferred into a 20 gallon reactor and triturated with anhydrous diethyl ether (2×30 L), removing the ether solution after each wash. The reactor is put under vacuum (3 mm Hg) for 0.5 hour to dispel most of the hydrogen chloride leaving ethyl 4-[5-[3-methoxy-4-[N,N-bis(1-methylethyl)aminocarbonyl]phenoxy]pentoxy]benzenecarboximidoate monohydrochloride as a thick purple oil.

Provenance & Evidence