Reference of 103626-03-5, Each compound has different characteristics, and only by selecting the characteristics of the compound suitable for a specific situation can the compound be applied on a large scale. 103626-03-5, name is Ethyl 1-methyl-3-oxo-2,3-dihydro-1H-pyrazole-4-carboxylate, This compound has unique chemical properties. The synthetic route is as follows.
A round bottom flask was charged with starting ethyl 3-hydroxy-1-methyl-4-pyrazolecarboxylate (100 mg, 0.588 mmol). The flask was placed under high vacuum for 5 min, then backfilled with nitrogen atmosphere. DMF (3 mL) was added, followed by sodium hydride (60% dispersion in mineral oil, 27 mg, 1.2 equiv.) at 20 C. The flask was stirred at 20 C. for 60 min, then 4-(2-iodoethyl)morpholine (184 mg, 1.3 equiv.) was added. The reaction was stirred at 80 C. for 16 hr. The reaction was removed from heating and allowed to cool to 20 C., then the reaction was quenched with water and extracted five times into ethyl acetate. The combined organic phases were washed with brine, dried over magnesium sulfate, filtered and concentrated in vacuo to provide 120 mg crude product. Silica gel TLC (95:5 dichloromethane:methanol) of the crude product indicated complete consumption of starting aminopyrazole (Rf ?0.60) and one new UV-active product (Rf 0.50). The resulting residue was dissolved in dichloromethane and purified by flash column chromatography (silica gel, 12 g, 0 to 10% methanol in dichloromethane). The major UV-active product eluted at 5% dichloromethane. Fractions were assayed by silica gel TLC. The fractions containing the major UV-active product were collected and concentrated in vacuo to give ethyl 1-methyl-3-(2-morpholinoethoxy)-1H-pyrazole-4-carboxylate (120 mg). 1H NMR (400 MHz, Chloroform-d) delta 7.63 (s, 1H), 4.37 (t, J=5.7 Hz, 2H), 4.21 (q, J=7.1 Hz, 2H), 3.71 (s, 3H), 3.72-3.69 (m, 4H), 2.82 (t, J=5.7 Hz, 2H), 2.61 (t, J=4.7 Hz, 4H), 1.28 (t, J=7.1 Hz, 3H). LCMS-ESI+ (m/z): [M+H]+ calculated for C13H21N3O4: 284.2; found: 284.1.
The chemical industry reduces the impact on the environment during synthesis Ethyl 1-methyl-3-oxo-2,3-dihydro-1H-pyrazole-4-carboxylate. I believe this compound will play a more active role in future production and life.
Reference:
Patent; Gilead Sciences, Inc.; Chu, Hang; Guerrero, Juan A.; Hurtley, Anna E.; Hwang, Tae H.; Jiang, Lan; Kato, Darryl; Kobayashi, Tetsuya; Knox, John E.; Lazerwith, Scott E.; Li, Xiaofen; Lin, David W.; Medley, Jonathan W.; Mitchell, Michael L.; Naduthambi, Devan; Newby, Zachary; Squires, Neil H.; Tsui, Vickie H.; Venkataramani, Chandrasekar; Watkins, William J.; Yang, Hong; (292 pag.)US2019/352271; (2019); A1;,
Pyrazole – Wikipedia,
Pyrazoles – an overview | ScienceDirect Topics