1-Ethyl-3-(3'-dimethylaminopropyl)carbodiimide → HCID 178452348, Verbindung

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

In a 250 mL round bottom flask with a stirbar was added Benzimidazole-5-carboxylic acid (2.00 g, 12.3 mmol), Boc-piperazine (2.41 g, 13.0 mmol, 1.05 eq), and Hunig's Base (3.78 mL, 27.1 mmol, 2.2 eq) in DMF (35 mL). After 5 minutes 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide (2.60 g, 13.6 mmol, 1.1 eq) was added portion wise and the dark solution stirred for 2 hr at 23° C. The reaction was diluted with Ethyl Acetate (250 mL) and partitioned between water (50 mL). The layers were separated and the organic washed with water (2×50 mL), brine (30 mL), dried (Na2SO4), and concentrated to a dark oil. The reaction was purified using Biotage MPLC system (40M column size, 0-20% Methanol/CH2Cl2 over 35 Column Volumes) giving the desired product as a beige solid (1.45 g, 4.39 mmol, 35.6%). 1H NMR (DMSO-d6, 400 MHz) δ 12.6 (s, 1H), δ 8.31 (s, 1H), δ 7.66-7.60 (m, 2H), δ 7.25 (bs, 1H), δ 3.60-3.25 (m, 8H), δ 1.40 (s, 9H); LRMS (m/z): 353 (M+Na), 331 (M+H), 275.

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