A new synthetic route of C7H7F3N2O2

Reference of 155377-19-8, These common heterocyclic compound, 155377-19-8, name is Ethyl 3-(trifluoromethyl)pyrazole-4-carboxylate, 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.

Example 118: Preparation of l-allyl-S-trifluoromethyl-lH-pyrazole^-carboxylic acid ethyl ester and 2-allyl-3-trifluoromethyl-2Hl-pyrazole-4-carboxylic acid ethyl ester3-Trifluoromethyl-lH-pyrazole-4-carboxylic acid ethyl ester (500 mg, 2.4 mmol) was dissolved in acetone and stirred. To the solution was added potassium carbonate(498 mg, 3.6 mmol), in one portion, followed by dropwise addition of allyl bromide (0.31 ml, 3.6 mmol). The reaction mixture was stirred at room temperature for 5 hours. The reaction mixture was poured into water and extracted twice with ethyl acetate. The combined organic extracts were dried over magnesium sulfate and concentrated to give a 9:1 mixture of l-allyl-3-trifluoromethyl-l//-pyrazole-4-carboxylic acid ethyl ester (isomer A) and 2-allyl-3-trifluoromethyl-2H-pyrazole-4-carboxylic acid ethyl ester (isomer B) (557 mg, 93% yield) as a yellow solid. Isomer A (major isomer) 1H-NMR (400 MHz, CDCl3): 1.39 (t, 3H, Me), 4.35 (q, 2H, CH2), 4.8 (d, 2H, CH2), 5.3-5.45 (dd, 2H, CH2), 6.05 (m, IH, CH), 8.01 (s, IH, CH) ppm. Isomer B (minor isomer) 1H-NMR (400 MHz, CDCl3): 1.39 (t, 3H, Me), 4.35 (q, 2H, CH2), 4.95 (d, 2H, CH2), 5.1-5.3 (dd, 2H, CH2), 6.05 (m, IH, CH), 7.98 (s, IH, CH) ppm.

Statistics shows that Ethyl 3-(trifluoromethyl)pyrazole-4-carboxylate is playing an increasingly important role. we look forward to future research findings about 155377-19-8.

Reference:
Patent; SYNGENTA LIMITED; WO2007/71900; (2007); A1;,
Pyrazole – Wikipedia,
Pyrazoles – an overview | ScienceDirect Topics