ETHYL 3-(TRIFLUOROMETHYL)PYRAZOLE-4-CARBOXYLATE synthesis
- Product Name:ETHYL 3-(TRIFLUOROMETHYL)PYRAZOLE-4-CARBOXYLATE
- CAS Number:155377-19-8
- Molecular formula:C7H7F3N2O2
- Molecular Weight:208.14
571-55-1
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155377-19-8
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Yield:155377-19-8 95%
Reaction Conditions:
with hydrazine hydrate in ethanol at 0 - 20; for 4.5 h;
Steps:
2.10. Ethyl 3-(trifluoromethyl)-1H-pyrazole-4-carboxylate (3f)
Hydrazine hydrate (10 g, 0.199 mol) was dissolved in ethanol (400 mL). This was cooled to 0 °C and a solution of ethyl 2-(ethoxymethylene)-4,4,4-trifluoro-3-oxobutanoate (47.03 g, 0.19 mol) in ethanol (200 mL) was added drop-wise over 90 min at 0 °C. The solution was left to warm to room temperature for 3 h and concentrated to dryness. The residue was dispersed in boiling cyclohexane (200 mL) and left to cool to room temperature. The precipitate was filtered, washed with cyclohexane and dried under vacuum at 75 °C to yield compound 3f as a yellow powder (38.67 g, 95%); mp 145 °C 1H NMR (CDCl3): 1.40 (t, 3H, J=7.0 Hz); 4.39 (q, 2H, J=7.0 Hz); 8.26 (s, 1H); 13.2 (s (br), 1H). 13C NMR (CDCl3): 14.0; 61.2; 113.4; 121.0 (q, J=268 Hz); 135.3; 142.0 (q, J=38 Hz); 160.8. HRMS: calcd For C7H7F3N2O2-H: 207.0381; Found: 207.0377.
References:
Guillou, Sandrine;Bonhomme, Frédéric J.;Ermolenko, Mikhail S.;Janin, Yves L. [Tetrahedron,2011,vol. 67,# 44,p. 8451 - 8457] Location in patent:experimental part
1048670-08-1
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155377-19-8
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122-51-0
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372-31-6
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155377-19-8
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372-31-6
474 suppliers
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155377-19-8
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16205-84-8
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155377-19-8
177 suppliers
$6.00/250mg