Chloro-6-formyl-3-ethyl ester

In the laboratory of N. Suzuki, the synthesis of several heterocyclic condensed 1,8-naphthyridine derivatives with potential antimicrobial activity was executed. The preparation of pyrazolo[3,4-b][1,8]naphthyridines required 7-chloro-6-formyl-3-ethyl ester as the precursor that was obtained by the Stephen reduction of the corresponding aromatic nitrile. The solution of the aromatic nitrile in chloroform was added to the solution of SnC /dry HCI gas in ether. After two days of stirring, the aldimine hexachlorostannane product was treated with warm water to obtain the desired aromatic aldehyde in modest yield. Heating of the aldehyde with methyl hydrazine afforded the pyrazole derivative. 

Pyrazole (3 chloro,4 carboxy,1 methyl 5 sulfonamide) halosulfuron Pyrazole (1.4 dimethyl,2 chloro, 3 formyl) fenpyroximate Pyrazole (2 methyl, 3 amino, 4 carboxy) pyrazosulfuron Pyrazole (2 methyl,4 carboxy, ethyl ester) pyrazosulfuron Pyrazole (1 methyl,2 ethyl,4 chloro 5 carboxy) tebufenpyrad 5 Pyrazolone (1.3 dimethyl) benzofenap, pyrazolinate, pyrazoxyfen Pyridazine (1 phenyl 3 hydroxy, 6 oxo) pyridafenthion... 

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