Synthetic Route of 105434-90-0,Some common heterocyclic compound, 105434-90-0, name is Ethyl 5-amino-1H-pyrazole-3-carboxylate, molecular formula is C6H9N3O2, 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.
Ethyl 6-(2-ethoxy-2-oxoethyl)-7-hydroxy-5-methylpyrazolo[l,5-a]pyrimidine- 2-carboxylate. A suspension of ethyl 5-amino-lH-pyrazole-3-carboxylate (35.5 g, 229 mmol, prepared according to WO 2008015271), diethyl 2-acetylsuccinate (51.2 niL, 275 mmol) and TsOHH20 (0.218 g, 1.144 mmol) in o-xylene (500 mL) was refluxed using a Dean-Stork condensor for 5 h. (Note: The suspension turned into a clear homogeneous solution and then in about 15 min a yellow solid started precipitated out of solution). Then, the reaction mixture was cooled, diluted with hexanes (250 mL), filtered, washed with hexanes and dried to afford ethyl 6-(2- ethoxy-2-oxoethyl)-7-hydroxy-5-methylpyrazolo[ 1 ,5-a]pyrimidine-2-carboxylate (53 g, 75 % yield) as light yellow solid. 1H NMR (500 MHz, DMSO-d6) delta 12.61 (br. s., 1H), 6.49 (s, 1H), 4.34 (q, J= 7.1 Hz, 2H), 4.09 (q, J= 7.1 Hz, 2H), 3.57 (s, 2H), 2.34 (s, 3H), 1.33 (t, J= 7.2 Hz, 3H), 1.19 (t, J= 7.0 Hz, 3H). LCMS (M+l) = 308.04.
These compound has a wide range of applications. It is believed that with the continuous development of the source of the synthetic route Ethyl 5-amino-1H-pyrazole-3-carboxylate, its application will become more common.