Electric Literature of 37622-90-5, A common heterocyclic compound, 37622-90-5, name is Ethyl 4-pyrazolecarboxylate, molecular formula is C6H8N2O2, 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.
To a solution of 1H-pyrazole-4-carboxylic acid ethyl ester (35.0 g, 0.25 mole) in THF (100 mL) was added suspension of sodium hydride (17.38 g, 0.43 mole) in THF (100 mL) solution under N2 at 25 C and stirred for one hour. Methyl iodide (24 mL, 0.38 mole) was added at RT and the reaction mixture was heated to 60-65 C for6 hours. Reaction mixture was quenched in to ice water (200 mL) and extracted with ethyl acetate (100 mL x 3). The combined organic phase was washed with water (50 mL), brine solution (50 mL), dried over Na2504 and concentrated under vacuum to obtain ethyl 1-methyl- 1H-pyrazole-4-carboxylate.Yield: 32.36 g (83 %); ?H – NMR (CDC13, 400 MHz) oe ppm: 1.30 – 1.33 (s, 3H), 3.91(s, 3H), 4.25 – 4.30 (q, 2H), 7.83 (s, 1H), 7.88 (s, 1H); Mass (mlz): 155.0 (M+H).
The basis of chemical reaction formula synthesis, the synthesis route is composed of some specific reactions and combined according to certain logical thinking. We look forward to the emergence of more reaction modes in the future.