Diisopropylcarbodiimide → HCID 54181953, compound

Participants

Reaction Steps

BAT-BM was prepared as follows. BAT acid (N9 -(t-butoxycarbonyl)-N6,N9 -bis(2-methyl-2-triphenylmethylthiopropyl)-6,9-diazanonanoic acid) (10.03 g, 10.89 mmol) and 75 mL of dry methylene chloride (CH2Cl2) were added to a 250 mL round-bottomed flask equipped with magnetic stir bar and argon balloon. To this solution was added diisopropylcarbodiimide (3.40 mL, 21.7 mmol, 199 mole %), followed by N-hydroxysuccinimide (3.12g, 27.1 mmol, 249 mole %). This solution was observed to become cloudy within 1 h, and was further incubated with stirring for a total of 4 h at room temperature. A solution of tris(2-aminoethyl)amine (30 mL, 200 mmol, 1840 mole %) in 30 mL methylene chloride was then added and stirring continued overnight. The reaction mixture was then concentrated under reduced pressure, and the residue partitioned between ethylacetate (150 mL) and 0.5M potassium carbonate (K2CO3 ; 150 mL). The organic layer was separated, washed with brine and concentrated to give the crude product N-[2-N',N'-bis(2-aminoethyl)aminoethyl)]-N9 -(t-butoxycarbonyl)-N6,N9 -bis(2-methyl-2-triphenylmethylthiopropyl)-6,9-diazanonanamide as a foam/oil.

Provenance & Evidence