Electric Literature of 1260243-04-6, The chemical industry reduces the impact on the environment during synthesis 1260243-04-6, name is Ethyl 5-amino-1H-pyrazole-4-carboxylate, I believe this compound will play a more active role in future production and life.
Intermediate 18: Ethyl 7-(tert-butyl)-5-(4-ethylphenyl)-4,7-dihydropyrazolo[1,5- a]pyrimidine-3-carboxylateTo a solution of Intermediate 17 (1 g, 4.620 mmol) and ethyl 5-amino-1 H-pyrazole-4- carboxylate (ALDRICH, 0.717 g, 4.620 mmol) in 2-(methyloxy)ethanol (10 mL) was added TFA (0.885 mL, 1 1 .560 mmol) with ice-water cooling. The reaction was refluxed overnight. LCMS showed reaction was finished. The mixture was diluted with EtOAc, washed with saturated NaHC03, water and brine, dried over MgS04 and concentrated in vacuo. Then, the crude material was purified by flash chromatography on silica gel (Merck cartridge, 20 g) and was eluted with mixtures of hexane/EtOAc (80:20). The desired fraction was collected and evaporated to obtain a yellow solid (1.1 g, 3.1 10 mmol, 67%). 1H NMR (400 MHz, CDCI3) delta ppm: 7.73 (s, 1 H), 7.44 (d, 2H), 7.25 (d, 2H), 5.09 (dd, 1 H), 4.78 (d, 1 H), 4.30 (q, 2H), 2.68 (q, 2H), 1.37 (t, 3H), 1.26 (t, 3H), 0.92 (s, 9H). [ES+ MS] m/z 353 (M+H)+.
In the field of chemistry, the synthetic routes of compounds are constantly being developed and updated. I will also mention this compound in other articles, Ethyl 5-amino-1H-pyrazole-4-carboxylate, other downstream synthetic routes, hurry up and to see.
Reference:
Patent; GLAXO GROUP LIMITED; ALVAREZ-RUIZ, Emilio; BALLELL-PAGES, Lluis; CASTRO-PICHEL, Julia; ENCINAS, Lourdes; ESQUIVIAS, Jorge; GAMO-BENITO, Francisco Javier; GARCIA-PALANCAR, Maria Cruz; REMUINAN-BLANCO, Modesto Jesus; WO2012/143522; (2012); A1;,
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