Hydrochloric Acid → 3,6-Bis(carboxymethyl)-9-(11-carboxy-1-n-hexyl-undecylcarbamoylmethyl)-3,6,9-triazaundecanedioic acid

Participants

Reaction Steps

15.33 g (38 mmol) of N3-(2,6-dioxomorpholinoethyl)-N6-(ethoxycarbonylmethyl)-3,6-diazaoctanedioic acid (Example 13a of EP 0 331 616) is suspended in 100 ml of dimethylformamide and mixed in an ice bath with 21.07 ml (152 mmol) of triethylamine and 11.36 g (38 mmol) of 12-aminooctadecanoic acid. After stirring overnight at room temperature, it is concentrated by evaporation in a vacuum, and the residue is absorptively precipitated with 500 ml of diethyl ether. It is suctioned off and the dried reaction product is dissolved in 50 ml of 2 n sodium hydroxide solution. After three hours of stirring, it is neutralized with dilute hydrochloric acid, evaporated to dryness in a vacuum and recrystallized from water. 15.64 g (61% of theory) of a gray powder is obtained.

Provenance & Evidence