3920-50-1

Colorless Solid

1H-?Pyrazole-?3-?carboxaldehyde is an intermediate used to prepare fused pyrrole carboxylic acids as novel, potent D-?amino acid oxidase (DAO) inhibitors. It is also a building block to synthesize α-?substituted benzylidenemalononitrile tyrphostins as potent inhibitors of EGF receptor and ErbB2?/neu tyrosine kinases.

The general procedure for the synthesis of 3-pyrazolecarboxaldehyde from 3-dimethoxymethyl-1H-pyrazole: 2.3 kg of formic acid was added slowly and dropwise to 15.5 kg of an aqueous solution containing 13.8 kg of 3-dimethoxymethyl-1H-pyrazole at 0-15 °C. Subsequently, the reaction mixture was magnetically stirred at 25 °C for 12 h. A light yellow solid was obtained upon completion of the reaction. The precipitate was separated by filtration and the filter cake was washed with 10 L of water to give 643 g of the final yellow solid product 3-pyrazolecarboxaldehyde.

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