Sodium Hydroxide → 4-[3-[(E)-(1-benzylindol-2-yl)methylideneamino]oxypropoxy]-2-hydroxybenzoic acid

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Reaction Steps

This compound was produced using similar methods as those used in Step 5, example 3, starting with 4-[3-({[(1E)-(1-benzyl-1H-indol-2-yl)methylidene]amino}oxy)propoxy]-2-hydroxybenzoic acid methyl ester (0.104 g, 0.23 mmol) and 2.5 M sodium hydroxide solution (3 mL). The crude material was purified by flash chromatography through silica gel using ethyl acetate/hexanes (10/90 with 1% formic acid gradient to 20/80 with 1% formic acid) followed by recrystallization one time from methylene chloride/hexanes to give 4-[3-({[(1E)-(1-benzyl-1H-indol-2-yl)methylidene]amino}oxy)propoxy]-2-hydroxybenzoic acid (0.063 g, 62%) as a white solid. mp=175-176° C. (dec). 1H NMR (400 MHz, DMSO-d6); δ 11.50 (bs, 1H), 8.41 (s, 1H), 7.68 (d, 1H), 7.60 (d, 1H), 7.48 (d, 1H), 7.25-7.16 (m, 5H), 7.06 (t, 1H), 6.99 (d, 2H), 6.91 (s, 1H), 6.47 (d, 1H), 6.44 (s, 1H), 5.75 (s, 2H), 4.18 (t, 2H), 4.05 (t, 2H), 2.00 (m, 2H). Mass spec; (ES+) m/z 445.1, (ES−) m/z 443.4. Elemental analysis; Calculated for C26H24N2O5: C, 70.26; H, 5.44; N, 6.30. Found: C, 69.86; H, 5.43; N, 6.09.

Provenance & Evidence