7-Methyl-8-oxononanoic acid → 6-(1,2-dimethyl-6,8-disulfo-1H-benzo[e]indol-1-yl)hexanoic acid

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Reaction Steps

(5,7-Disulfo-2-naphthyl)hydrazinium chloride (2.0 g), 7-methyl-8-oxononanoic acid (1.5 g) and acetic acid (15 ml) were heated from 80-140° C. for a total of 24 hrs. After evaporation of the solvent under vacuum, the residue was triturated with 2-propanol to give a pink solid. This solid was collected by filtration, washed with 2-propanol, then excess diethyl ether and dried under vacuum over phosphorus pentoxide. Yield of crude product=1.96 g. This was purified as required by preparative HPLC (RPC18. Water/MeCN/TFA) to give pure product. 1H-nmr (D2O) δ 0.25-0.4 (1H, broad m), 0.5-0.65 (1H, broad m), 1.00 (2H, m), 1.25 (2H, m), 1.78 (3H, s), 2.06 (2H, t), 2.35-2.5 (1H, broad m), 2.65-2.8 (1H, broad m), 2.90 (3H, s), 8.05 (1H, d), 8.58 (1H, d), 8.70 (1H, d) and (8.97 (1H, d). MS (LCMS) MH+470. Acc. Mass: MH+470.0931 (−2.6 ppm for C20H24NO8S2).

Provenance & Evidence