6-((2-Methyl-1-oxoallyl)amino)hexanoic acid → HCID 58173699, compound

Participants

Reaction Conditions

Reaction Steps

A suspension of 6-(methacryloylamino)caproic acid (2.80 g, 14.0 mmol), 1,4,7-tris(tert-butoxycarbonylmethyl)-1,4,7,10-tetraazacyclododecane hydrobromide (7.75 g, 13.0 mmol), N,N-dimethylaminopyridine (1.83 g, 15.0 mmol) and 5 mg BHT in 60 ml dichloromethane was cooled to −5° C. and 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride (2.88 g, 15.0 mmol) was added portionwise under stirring. To complete the reaction, the mixture was stirred for 2 h at −5° C. and over night at room temperature. 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride (1.00 g, 6.44 mmol) and N,N-dimethylaminopyridine (0.6 g, 4.9 mmol) each time were then added 3 more times at intervals of 2 h and finally left to be stirred for 6 h. The solution was washed 3 times with in each case 50 ml saturated aqueous NaCl solution, dried over anhydrous Na2SO4, filtered, concentrated on the rotary evaporator after the addition of 5 mg BHT and dried under fine vacuum. 10.3 g of a yellowish oil was obtained which was purified twice by chromatography (silica gel 60, 0.015-0.040 mm, acetone). The acetone was again distilled off on the rotary evaporator after the addition of 5 mg BHT and the product dried in fine vacuum. 6.13 g (8.8 mmol, 68% yield) of a yellow, highly viscous oil was obtained (HPLC purity: 95%).

Provenance & Evidence