Diisopropylethylamine → 3-{[(2,3-Diaza-spiro[4.4]non-3-en-2-yl)-ethylamino-methylene]-sulfamoyl}-benzoic acid methyl ester

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Reaction Steps

To a solution of 4.07 g 3-chlorosulfonyl-benzoic acid methyl ester in 150 mL DCM were added 17.69 mL (6.0 equiv.) DiPEA and 4.00 g (1.0 equiv.) N-ethyl-2,3-diaza-spiro[4.4]non-3-ene-2-carboxamidine. The reaction mixture was stirred overnight at room temperature under N2 atmosphere, and extracted with water. The organic phase was dried over Na2SO4 and evaporated, and the residue was purified by automated flash chromatography (EtOAc/PA 1:1) to give 4.80 g (71%) of a yellow solid. 1H NMR (400 MHz, CDCl3) δ 1.16 (t, J=8 Hz, 3H), 1.62-1.86 (m, 8H), 3.42-3.53 (m, 2H), 3.87 (s, 2H), 3.95 (s, 3H), 6.83 (s, 1H), 6.83-6.95 (broad peak, 1H), 7.56 (t, J=8 Hz, 1H), 8.13-8.18 (m, 2H), 8.61 (s, 1H).

Provenance & Evidence