Triethylamine → 3-tert-Butylamino-4-(2,6-dichloro-benzylamino)-cyclobut-3-ene-1,2-dione

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Reaction Steps

To 2,6-dichlorobenzylamine hydrochloride from Example 5, Step 2 (1.06 g, 5.0 mmol) in tetrahydrofuran (10 mL ) was added triethylamine (0.505 g, 5.0 mmol) followed by 3-butoxy-4-tert-butylamino-cyclobut-3-ene-1,2-dione (1.13 g, 5.0 mmol, Example 1) and stirring was continued for approximately 16 hours. The reaction mixture was freed of solvent and the residue was triturated with water, with diethyl ether and dried. The white solid thus isolated was crystallized twice from methanol to give 0.623 g (38%) of the title compound as a white solid: mp 265°-6° C. dec (softens 263° C.); 1H NMR (DMSO-d6) δ7.55 (d, 2H), 7.49 (br m, 1H), 7.42 (m, 2H), 5.05 (d, 2H), 1.34 (s, 9H) ppm. IR (KBr): 3185, 1785, 1660 cm-1 ; MS (m/z) 326/328/330 (M+). HPLC indicates a major component (99.9%).

Provenance & Evidence