Diisopropylethylamine → (Z)-3-(3-(3,5-bis(trifluoromethyl)phenyl)-1H-1,2,4-triazol-1-yl)-N'-(1,1-dioxotetrahydrothiophen-3yl)acrylohydrazide

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Reaction Conditions

Reaction Steps

A 50-mL, 3-necked, round-bottomed flask charged with a solution of (Z)-3-(3-(3,5-bis(trifluoromethyl)phenyl)-1H-1,2,4-triazol-1-yl)acrylic acid (0.5 g) in EtOAc (20.0 mL) was treated with 2-(1,1-dioxotetrahydrothiophen-3-yl)hydrazine (0.3 g, 1.2 eq.). The mixture was cooled to −60° C. and treated simultaneously with T3P (50% in EtOAc; 2.0 mL, 2 eq.) and DIPEA (1 mL, 4 eq.). The reaction mixture was stirred for 30 min at −60° C. before being concentrated under reduced pressure (35° C., 20 mmHg) to afford 0.60 g of a solid residue. Purification by column chromatography (SiO2; elution with MeOH:CH2Cl2; desired compound eluted at 5% MeOH in CH2Cl2) afforded 100 mg (yield=15%) (Z)-3-(3-(3,5-bis(trifluoromethyl)phenyl)-1H-1,2,4-triazol-1-yl)-N′-(tetrahydrothiophen-1-1-dioxide-3-yl)acrylohydrazide. 1H NMR (400 MHz, CD3OD) δ=9.57 (s, 1H), 8.64 (s, 2H), 8.10 (s, 1H), 7.34-7.36 (d, J=10.4 Hz, 1H), 5.89-5.92 (d, J=10.8 Hz, 1H), 4.01 (m, 1H), 3.04-3.26 (m, 4H), 2.27-2.34 (m, 2H). LCMS for C17H15F6N5O3S [M+H]+ 484.40. found 483.39 (RT 2.63 min, purity: 66.39%).

Provenance & Evidence