p-Toluenesulfonic acid monohydrate → Methyl 4-[(2-{1-[2-bromo-5-(4-t-butylphenyl)-4-hydroxy-3-thienyl]ethylidene}hydrazino)carbonyl]benzoate

Participants

Reaction Steps

To a suspension of 2-bromo-5-(4-t-butylphenyl)-4-hydroxy-3-methylcarbonylthiophene (1.00 g, 2.83 mmol) synthesized in Reference Synthetic Example 55 and 4-hydrazinocarbonylmethylbenzoate (550 mg, 2.83 mmol) in isopropyl alcohol (28.3 mL), tosylic acid monohydrate (146 mg, 0.85 mmol) was added, and the mixture was heated with reflux for about 1 hour. The reaction solution was concentrated, and then purified with a silica gel column chromatography (chloroform, and then chloroform/ethyl acetate=95/5) to obtain the desired product as a yellow solid (935 mg, yield 62%).

Provenance & Evidence