Electric Literature of 138907-68-3, These common heterocyclic compound, 138907-68-3, name is Ethyl 5-amino-1-(4-fluorophenyl)-1H-pyrazole-4-carboxylate, its 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.
PREPARATION G Ethyl 1-(4-fluorophenyl)-1H-pyrazole-4-carboxylate A stirred suspension of ethyl 5-amino-1-(4-fluoro-phenyl)-1H-pyrazole-4-carboxylate (7.48 g, 30.0 mmole), prepared as described in Preparation A, above, and isopentyl nitrite (7.03 g, 60.0 mmole) in 80 ml of tetrahydrofuran was refluxed for twenty-four hours and then evaporated in vacuo. The residue was triturated with 50 ml of methanol and filtered to furnish 5.18 g (74% yield) of off-white solid. The sample was recrystallized from ethanol, m.p. 119-21 C. Analysis: Calculated for C12 H11 FN2 O2: C, 61.53; H, 4.73; N, 11.96%. Found: C, 61.41; H, 4.51; N, 11.95%.
The synthetic route of 138907-68-3 has been constantly updated, and we look forward to future research findings.