Lithium Hydroxide → 3-({5-[2-(Pyridin-2-ylamino)-ethylcarbamoyl]-thiophene-2-carbonyl}-amino)-2-(2,4,6-trimethyl-benzenesulfonylamino)-propionic acid methyl ester

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Reaction Steps

5-[2-(Pyridin-2-ylamino)-ethylcarbamoyl]-thiophene-2-carboxylic acid methyl ester was hydrolyzed with LiOH as described before. To a mixture of 5-[2-(Pyridin-2-ylamino)-ethylcarbamoyl]-thiophene-2-carboxylic acid (38 mg, 0.12 mmol), salt of 3-amino-2-(2,4,6-trimethyl-benzenesulfonylamino)-propionic acid 2-tert-butoxycarbonylamino-ethyl ester (47 mg, 0.14 mmol), hydroxybenzotriazole (21 mg, 0.15 mmol) in DMF (20 mL), was added 1-(3-dimethylamino) propyl)-3-ethylcarbodiimide hydrochloride (29 mg, 0.15 mmol). The reaction was stirred overnight at room temperature. Insolubles were removed by filtration and the solvent was evaporated. Purification of the residue on silica gel (10% MeOH/EtOAc) gave 60 mg (87%) of pure 3-({5-[2-(Pyridin-2-ylamino)-ethylcarbamoyl]-thiophene-2-carbonyl}-amino)-2-(2,4,6-trimethyl-benzenesulfonylamino)-propionic acid methyl ester. 1HNMR (300 MHz, CDCl3) δ: 2.22 (s, 3H), 2.61 (s, 6H), 3.55 (m, 4H), 3.82 (m, 1H), 4.09 (m, 1H), 6.50(d, 1H), 6.69(t, 1H), 6.90(s, 2H), 7.05(t, 1H), 7.40(m, 3H), 8.10 (s, 1H), 8.43(m, 1H).

Provenance & Evidence