反应详情

To a solution of 250 mg (0.723 mmol) of 1,4,7-triscarboxymethyl-1,4,7,10-tetraazacyclododecane in 2.9 ml of methanol was added 220 mg (1.59 mmol) of potassium carbonate. To the resulting mixture was added 308 mg (2.17 mmol, 3 equiv) of methyl iodide. Within a short time, most of the solids dissolved. After 15 hours at 21° C., a mass of crystals had separated. Additional methanol was added (2 ml) to dissolve the solid. After 23 hours, an additional 102 mg (0.72 mmol) of methyl iodide was added. After an additional 16 hours, the solution was acidified with concentrated hydrochloric acid and the volatiles were removed on the rotary evaporator. The residue was extracted with methanol, filtered, and the methanol evaporated. The residue was crystallized twice from methanol/acetone yielding 56 mg (0.16 mmol) of a colorless solid, melting point 215°-240° (dec.). 13C NMR (D2O, ppm vs TMS): 177.2, 171.1, 57.2, 56.5, 54.1, 52.6, 50.1, 49.9, 43.7.Mass spectrum (FAB): m/e 359 (M-H) and 361 (M+H).

1. dissolutionWithin a short time, most of the solids dissolved
2. customa mass of crystals had separated
3. additionAdditional methanol was added (2 ml)
4. dissolutionto dissolve the solid
5. waitAfter 23 hours
6. waitAfter an additional 16 hours
7. customthe volatiles were removed on the rotary evaporator
8. extractionThe residue was extracted with methanol
9. filtrationfiltered
10. customthe methanol evaporated