5-AMINO-1-(4-CHLORO-BENZYL)-1H-PYRAZOLE-4-CARBOXYLIC ACID ETHYL ESTER synthesis
- Product Name:5-AMINO-1-(4-CHLORO-BENZYL)-1H-PYRAZOLE-4-CARBOXYLIC ACID ETHYL ESTER
- CAS Number:137278-71-8
- Molecular formula:C13H14ClN3O2
- Molecular Weight:279.72
Yield:137278-71-8 11%
Reaction Conditions:
in ethanol at 80;
Steps:
3-1.2 Preparation of ethyl 5-amino-1-(4-chlorobenzyl)-1H-pyrazole-4-carboxylate
A solution of (E)-ethyl2-cyano-3-ethoxyacrylate (1 .64 g, 9.708 mmol) and (4-chlorobenzyl) hydrazine (2 g, 9.708 mmol) in ethanol was stirred at 80° C for overnight. The solvent was removed under reduced pressure. The crude compound was purified by column chromatography over silica gel (100-200 mesh) using a solvent gradient of 20% ethyl acetate in pet-ether as eluent to afford 400 mg (1 1 %) of ethyl 5-amino-1-(4-chlorobenzyl)-1H-pyrazole-4- carboxylate as an off-white solid.1H NMR (400 MHz, DMSO-d6): 1 .24 (t, J = 7.0 Hz, 3H), 4.16 (q, J = 7.0 Hz, 2H), 5.17 (s, 2H), 6.41 (br s, 2H), 7.16 (d, J = 8.4 Hz, 2H), 7.40 (d, J = 8.4 Hz, 2H), 7.50 (s, 1 H).LC-MS: m/z 280.1 (M+H)+.
References:
WO2014/167528,2014,A1 Location in patent:Paragraph 64
104-83-6
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