Electric Literature of 400755-44-4,Some common heterocyclic compound, 400755-44-4, name is 1-Ethylpyrazole-3-carboxylic Acid, molecular formula is C6H8N2O2, 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.
To a solution of 5-(3-chloro-5-fluorobenzyl)pyridin-2-amine (0.189 g, 0.8 mmol), 1 -ethyl- 7/-/-pyrazole-3-carboxylic acid (0.1 68 g, 1 .2 mmol) and A/,A/-diisopropylethylamine (0.310 g, 2.4 mmol) in A/,A/-dimethylformamide (5 ml_) at room temperature was added 1 -[b/’s(dimethylamino) methylene]- 7/-/-1 ,2, 3-triazolo[4,5-b]pyridinium 3-oxid hexafluorophosphate (0.456 g, 1 .2 mmol under nitrogen. The reaction mixture was stirred at 90 C for 3 h. The reaction mixture was diluted with ethyl acetate (80 ml_) and washed with brine (30 ml_ x 3). The combined organic layers were dried over sodium sulfate, filtered and concentrated. The crude sample was dissolved in minimal A/,A/-dimethylformamide and purified via prep-HPLC (Boston C18 21 *250 mm 10 pm column. The mobile phase was acetonitrile/10 mM ammonium acetate aqueous solution) to give A/-(5-(3-chloro-5-fluorobenzyl)pyridin-2-yl)-1 -ethyl- 7/-/-pyrazole-3-carboxamide (44.7 mg, 0.13 mmol, 26%) as a pale white solid. 1 H NMR (500 MHz, Dimethylsulfoxide-c/6) d 9.55 (s, 1 H), 8.32 (s, 1 H), 8.1 1 (d, J =8.5 Hz, 1 H), 7.94 (d, J = 2.0 Hz, 1 H), 7.76 (dd, J/ = 1 .5 Hz, J2 = 8.0 Hz, 1 H), 7.25-7.28 (m, 2H), 7.17 (d, J = 9.5 Hz, 1 H), 6.85 (d, J = 2.0 Hz, 1 H), 4.25 (dd, Ji = 7.0 Hz, J2 = 14.5 Hz, 2H), 3.97 (s, 2H), 1 .43 (t, J = 7.0 Hz,3H); LCMS (ESI) m/z: 359.1 [M+H]+.
The synthetic route of 400755-44-4 has been constantly updated, and we look forward to future research findings.