5334-40-7, Each compound has different characteristics, and only by selecting the characteristics of the compound suitable for a specific situation can the compound be applied on a large scale. 5334-40-7, name is 4-Nitro-1H-pyrazole-3-carboxylic acid, This compound has unique chemical properties. The synthetic route is as follows.
General procedure: 4-Nitrobenzyl bromide (46.3mmol) was dissolved in dichloromethane (100mL). The solution was added to the mixture of relative amine (47.0mmol) and triethylamine (70.3mmol) in dichloromethane (20ml). The reaction mixture was stirred at r. t. for 24 h and was extracted with dichloromethane (100ml¡Á3). After removal of the solvent, the residue was crystallized from ethanol, giving yellow powder. Compounds 1 and 2 were used for further reaction without purification. To a suspension of compounds 1?2 (36.2mmol) in 95percent ethanol (100ml), 85percent NH2NH2¡¤H2O (362mmol), 95percent ethanol (100ml) and iron (III) oxide hydroxide (FeO(OH)/C, 2.0g) were added and heated to reflux. When TLC analysis showed complete conversion of the starting material, the reaction mixture was filtrate through Cellit and the filtrate was concentrated in vacuum. The crude product was purified by silica gel colum chromatography (DCM/MeOH) to yield the title compound (3 and 4) as white solid. The mixture of compound 4 (1eq, 18.5mmol), 4-Nitro-1H-pyrazole-3-acid (1.1equiv, 20.4mmol), EDC (1.2equiv, 22.2mmol), HOBT (1.2equiv, 22.2mmol) in DMF (50ml) was stirred for 24h. The ice water (100ml) was added to the reaction mixture. A large amount of yellow solid precipitation (compound 8) was acquired. Compound 8 was used without further purification. Compounds 8 was reduced by the same process as compound 4, and then the resulting compound 12 was purified by column chromatography on silica gel, eluted with the appropriate solvent.
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