Ethanol 2 B (42 L) is added to the reactor and the ethyl 4-[5-[3-methoxy-4-[N,N-bis(1-methylethyl)aminocarbonyl]phenoxy]-pentoxy]benzenecarboximidoate monohydrochloride is dissolved. The solution is cooled to 5° C. and anhydrous ammonia is bubbled into the solution for 7.5 hours until saturation is obtained. After stirring overnight in the ice bath, and ammonia addition is continued another 7.5 hours at 5° C. The reaction mixture is followed by TLC (CH2Cl2 /MeOH, 9:1) using silica plates. A total of four days is required for completion of reaction with periodic resaturation with ammonia gas. The reaction mixture is filtered and the filtrate divided into two equal portions. Concentration in vacuo (55° C., 3 mm Hg) gives an oily viscous suspension which is charged into a 20 gallon reactor. This is admixed with hydrochloric acid (12 N, 560 ml), diluted with water (44 L). At this point, the compound dissolves (pH is 1.62). The solution is washed with diethyl ether (3×18 L), and the pH adjusted to 12.6 with a 6 N sodium hydroxide solution (3.0 L). The oily suspension crystallizes after stirring overnight at 20° C. The product is filtered, washed with water (5×4 L) and dried in vacuo (60° C. 3 mm Hg) to give the product. The second half of the reaction mixture is worked up in a similar manner to give 4-[5-[4-(aminoiminomethyl)phenoxy]pentoxy]-3-methoxy-N,N-bis(1-methylethyl)-benzamide is obtained, mp 112°-114° C. HPLC indicates a purity of 98.5%.
