4-Formylbenzoic acid → Bavisant

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

4-(4-Cyclopropyl-piperazine-1-carbonyl)-benzaldehyde. A mixture of 4-formyl-benzoic acid (54.4 g), toluene (500 mL), N,N-dimethylformamide (DMF) (3.6 mL), and thionyl chloride (30.4 mL) was heated at 60° C. for 2 h and then was cooled to 5° C. In a separate flask, a 5° C. mixture of NaOH (50.7 g), water (550 mL), and toluene (150 mL) was treated with 1-cyclopropyl-piperazine dihydrochloride (70.0 g) in portions while the temperature was maintained below 10° C. After the addition was complete, the mixture was cooled to 5° C. and treated with the crude acyl chloride solution prepared as above at a rate such that the temperature did not exceed 10° C. After the addition was complete, the mixture was allowed to warm to rt and was stirred overnight. The biphasic mixture was basified to pH ˜10 with 1 N NaOH (300 mL). The layers were separated and the aqueous layer was extracted with toluene (100 mL×2). The combined organic layers were washed with brine (200 mL), dried (Na2SO4), and concentrated to give the title compound as pale yellow viscous oil (56.0 g, 62%). HPLC: RT=5.19 min. MS (ESI): mass calcd. for C15H18N2O2, 258.14; m/z found, 258.9 [M+H+]. 1H NMR (400 MHz, CDCl3): 10.1 (s, 1H), 7.94 (pseudo d, J=8.2 Hz, 2H), 7.56 (pseudo d, J=8.1 Hz, 2H), 3.77 (br s, 2H), 3.33 (br s, 2H), 2.71 (br s, 2H), 2.55 (br s, 2H), 1.66 (ddd, J=10.2, 6.6, 3.7 Hz, 1H), 0.52-0.46 (m, 2H), 0.45-0.40 (br s, 2H).

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