Reference of 57999-06-1, These common heterocyclic compound, 57999-06-1, name is 4-Phenyl-1H-pyrazol-5-amine, 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.
General procedure: The suitable 4-substituted-5-aminopyrazoles (1c-f, 1h-p) (20 mmoles) were diazotized as usual and the solution of diazonium salt was treated with of sodium acetate (24 mmoles) at room temperature and stirred until to complete dissolution. At this solution was then added ethyl acetoacetate (20.0 mmoles) in ethanol and stirred for 1 h at room temperature. The final compounds were recovered by filtration after addition of water or by extraction if a precipitate was not formed. Starting from 1f, in this reaction condition, a byproduct is formed and identified as 1H-Benzo[h]pyrazolo[3,4-c]cinnoline, 10. The unambiguous synthesis of this latter was obtained as described below. 5.6.1 Ethyl 4-methyl-8-(pyridin-3-yl)pyrazolo[5,1-c][1,2,4]triazin-3-carboxylate, 7c ;Yellow crystals; TLC eluent: dichloromethane/methanol 10:1 v/v; 1H NMR (CDCl3) delta 9.41 (d, J?=?2.0?Hz, 1H, Py); 8.77 (s, 1H, H-2); 8.70 (dd, J?=?7.8, 1.7?Hz, 1H, Py); 8.22 (dd, J?=?4.9, 1.7 1H, Py); 7.49 (dd, J?=?7.8, 4.9, 1H, Py); 4.60 (q, J?=?7.0?Hz, 2H, CH2); 3.27 (s, 3H, CH3); 1.60 (t, J?=?7.0?Hz, 3H, CH3). ;Anal C, H, N.
The synthetic route of 57999-06-1 has been constantly updated, and we look forward to future research findings.
Reference:
Article; Guerrini, Gabriella; Ciciani, Giovanna; Daniele, Simona; Martini, Claudia; Costagli, Camilla; Guarino, Chiara; Selleri, Silvia; Bioorganic and Medicinal Chemistry; vol. 26; 9; (2018); p. 2475 – 2487;,
Pyrazole – Wikipedia,
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