General procedure for the preparation of benzamides 2, 4, and 21–2step step three: To a mixture of the appropriate acid (1 equiv) and 20 (1 equiv) in CH₂Cl₂ (5 mL mmol ?1 ) was added HATU (1.2 equiv) and DIPEA (3 equiv) at 0 °C and after which it was stirred at 29 °C for 8 h. The combined organic layers were dried over anhydrous Na₂SO₄ and filtered. The EtOAc was evaporated under reduced pressure and the resulting crude product was purified by column chromatography over SiO₂ (hexane/EtOAc as eluent) to afford the desired amides 2, 4, 21–23.

New solvent are evaporated less than less tension together with ensuing rough device refined by column chromatography towards SiO

Ethyl 3-(3,4-dimethoxy-benzamido)benzoate (2): Compound 2 was synthesized according to the general procedure by using 19 (0.05 g, 0.twenty-eight mmol) and was obtained as a yellow solid (0.63 g, 0.21 mmol, 76 %). 1 H NMR (400 MHz, CDCl₃): ?=8.19–8.00 (m, 3H), 7.80 (d, J=7.5 Hz, 1H), 7.49 (s, 1H), 7.47–7.37 (m, 2H), 6.87 (d, J=8.4 Hz, 1H), 4.35 (q, J=7.1 Hz, 2H), 3.92 (s, 6H), 1.37 (t, J=7.0 Hz, 3H). 13 C NMR (101 MHz, CDCl₃): ?=, , , , , , , , , , , , , , , , ; HRMS (ESI + ) [M+H] + C₁₈NO₅ calculated Da, found: m/z. Continue reading →