1621-91-6,Some common heterocyclic compound, 1621-91-6, name is 1H-Pyrazole-3-carboxylic acid, molecular formula is C4H4N2O2, traditional synthetic route has been very mature, but the traditional synthetic route has various shortcomings, such as complicated route, low yield, poor purity, etc, below Introduce a new synthetic route.
General procedure: Into a 1L open reactor was added 500g of carboxylic acid raw material (chemically pure) and stirring was turned on (600 r/min) from the reactorThe bottom is continuously fed with ammonia gas (chemical purity, water content of 5.1% by weight, flow rate of 100 g/min) to the carboxylic acid feed. After the reaction was allowed to proceed for TC hours at the reaction temperature TA, ammonia gas flow was stopped. The contents of the reactor were sampled and subjected to nuclear magnetic proton and elemental analysis to characterize the amide intermediate. Specific reaction conditions and characterization results are shown in Table A-1, Table A-2, Table A-3, Table A-4, Table A-5 and Table A-6. These characterization results show that the amide intermediates obtained have an extremely high purity (above 99%).In this embodiment, the ammonia gas can be directly replaced with waste ammonia gas (from Yangzi Petrochemical Plant, containing approximately50wt% of ammonia gas, the rest were toluene, oxygen, nitrogen, steam, carbon monoxide, and carbon dioxide, and the flow rate of this waste ammonia was 130g/min).
These compound has a wide range of applications. It is believed that with the continuous development of the source of the synthetic route 1H-Pyrazole-3-carboxylic acid, its application will become more common.