Some common heterocyclic compound, 31037-02-2, name is Ethyl 5-amino-1-methyl-1H-pyrazole-4-carboxylate, molecular formula is C7H11N3O2, 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. Safety of Ethyl 5-amino-1-methyl-1H-pyrazole-4-carboxylate
Carboxylate 62 (20.0 g, 118 mmol) in ethanol (100 mL) was treated with aqueous sodium hydroxide (50 mL, 3 M). The reaction mixture was heated to reflux and allowed to stir for 2 h and the ethanol removed under reduced pressure. The aqueous solution was cooled to 0 C and acidified with HCl (3 M) to pH 5. The white precipitate was collected by filtration and heated neat to 185 C in Kugelrohr oven under vacuum (1 mmHg) to afford titled compound 22 (10.0 g, 87%) as a light brown solid. MP: 73 – 74 C; IR (Diamond Cell, neat): 3395, 3134, 1643, 1556, 1517, 1431, 1344, 1268, 1207, 999, 928, 758, 632 cm-1; 1H NMR (300 MHz, Chloroform-d) delta 7.21 (d, J = 2.0 Hz, 1H), 5.49 (d, J = 2.0 Hz, 1H), 3.62 (s, 3H), 3.50 (br. s, 2H); 13C NMR (75 MHz, Chloroform-d) delta 144.6 (C), 138.2 (CH), 91.2 (CH), 34.3 (CH3); LRMS (ESI+) m/z: 98 (100, [M + H]+), 120 (50, [M + Na]+). This data matched that previously reported. 3
These compound has a wide range of applications. It is believed that with the continuous development of the source of the synthetic route 31037-02-2, its application will become more common.
Reference:
Article; Katte, Timothy A.; Reekie, Tristan A.; Werry, Eryn L.; Jorgensen, William T.; Boyd, Rochelle; Wong, Erick C.N.; Gulliver, Damien W.; Connor, Mark; Kassiou, Michael; European Journal of Medicinal Chemistry; vol. 136; (2017); p. 330 – 333;,
Pyrazole – Wikipedia,
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