Hydrazine hydrate (1:1) → HCID 178515601, compound
Reaction equation
[Cl:1][C:2]1[CH:7]=[CH:6][C:5]([C:8](=O)[CH2:9][C:10](OCC)=[O:11])=[C:4]([F:16])[CH:3]=1.O.[NH2:18][NH2:19]>C(O)C>[Cl:1][C:2]1[CH:7]=[CH:6][C:5]([C:8]2[CH:9]=[C:10]([OH:11])[NH:19][N:18]=2)=[C:4]([F:16])[CH:3]=1Participants
4
Reactant 2
Product 1
Reagents, catalysts & solvents 1
Procedure
428.4 g of ethyl 3-(4-chloro-2-fluorophenyl)-3-oxopropionate were initially charged in 1400 ml of ethanol. Over a period of 15 min, 92 g of hydrazine hydrate were added dropwise, the mixture was stirred at room temperature overnight, the precipitated solid was filtered off and the filtrate was concentrated to ⅓ of its original volume. The mixture was stirred for another two nights, the resulting solid was filtered off with suction and the filtrate was again concentrated to ⅓ of its original volume. This gave a total of 289.1 g (77.7%) of 3-(4-chloro-2-fluorophenyl)-5-hydroxy-1H-pyrazole as a colorless solid. M.p.: 194° C.