Triethylamine → 3-(2,6-Dichloro-benzylamino)-4-(1,1-dimethyl-propylamino)-cyclobut-3-ene-1,2-dione

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Reaction Steps

To 2,6-dichlorobenzylamine hydrochloride of Example 4, Step 2 (1.06 g 5.0 mmol) in tetrahydrofuran (10 mL) was added triethyl amine (0.505 g, 5.0 mmol) followed by 3-butoxy-4-(1,1-dimethyl-propylamino)-cyclobut-3-ene-1,2-dione (1.20 g, 5.0 mmol, Example 3) and stirring was continued at room temperature for approximately 16 hours. The reaction mixture was freed of solvent and the residue was triturated successively with water and with diethyl ether, and then dried. The resulting light yellow solid was recrystallized from acetonitrile three times to provide 0.755 g (44%) of the title compound as a white solid: mp 239°-241° C. (dec); 1H NMR (DMSO-d6): δ7.57 (m, 1H), 7.55 (m, 1H), 7.52 (br m, 1H),m 7.43 (m, 1H), 7.30 (s, br, 1H), 5.07 (d, 2H), 1.65 (q, 2H), 1.28 (s, 6H), 0.80 (t, 3H) ppm. IR (KBr): 3250, 1785, 1660 cm-1 ; MS (m/z) 340/342/344 (M+). HPLC indicates a major component (99.7%).

Provenance & Evidence