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

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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 2N hydrochloric acid. The aqueous phase is extracted three times with CH2Cl2. After the methylene chloride phase has been washed with 2N 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