Hydrochloric Acid → Methyl 4-cyclopentylidenehydrazino-2-[3-(4,6-dimethoxypyrimidin-2-yl)-ureidosulfonyl]benzoate

Participants

Reaction Steps

1.5 g (4.8 mmol) of methyl 4-cyclopentylidenehydrazino-2-sulfamoylbenzoate and 1.6 g (5.8 mmol) of phenyl N-(4,6-dimethoxypyrimidin-2-yl)carbamate are initially introduced into 20 ml of acetonitrile. 1.6 g (10.6 mmol) of 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) are added dropwise at 0° C. and the mixture is stirred at this temperature for 2 hours. It is poured into water and the pH is brought to 2-3 with 2 N hydrochloric acid. The aqueous phase is extracted three times with CH2Cl2. After the methylene chloride phase has been washed with 2 N hydrochloric acid and water, it is dried and evaporated. The residue is triturated with diisopropyl ether. After filtering off with suction and drying, 1.55 g (65% of theory) of methyl 4-cyclopentylidenehydrazino-2-[3-(4,6-dimethoxypyrimidin-2-yl)-ureidosulfonyl]benzoate of melting point 168-170° C. (decomposition) are obtained.

Provenance & Evidence