Reference of 1260243-04-6, These common heterocyclic compound, 1260243-04-6, name is Ethyl 5-amino-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.
Step 3: preparation of ethyl 5-acetamido-1 H-pyrazole-4-carboxylate. A mixture of ethyl 5-amino-1H-pyrazole-4-carboxylate (100 g, 0.65 mol) and acetyl chloride (441.2 g, 5.62 mol) at 0°C was heated to reflux for 4h. The reaction was concentrated in vacuo to remove excess acetyl chloride. Water (1.0 L) was added and the mixture was stirred for 16 h, after which it was filtered to afford the title compound as an off white solid (120g, 94percent). MS (M+H) m/z 198. 1H NMR (400 MHz, CDCI3) 6 ppm: 9.57(1 H, s), 7.75 (1H, s), 4.33-4.28 (2H, q, J = 7.08), 2.27 (3H, s), 1 .37-1.34 (3H, s).
The synthetic route of 1260243-04-6 has been constantly updated, and we look forward to future research findings.
Reference:
Patent; PFIZER INC.; SPRINGER, John Robert; DEVADAS, Balekudru; GARLAND, Danny James; GRAPPERHAUS, Margaret Lanahan; HAN, Seungil; HOCKERMAN, Susan Landis; HUGHES, Robert Owen; SAIAH, Eddine; SCHNUTE, Mark Edward; SELNESS, Shaun Raj; WALKER, Daniel Patrick; WAN, Zhao-Kui; XING, Li; ZAPF, Christoph Wolfgang; SCHMIDT, Michelle, Ann; WO2014/68527; (2014); A1;,
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