5-chloro-2-pyrrolidin-1-ylbenzaldehyde

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A 100 mL round-bottom flask was charged with 5-chloro-2-(pyrrolidin-1-yl)benzaldehyde (1.80 g, 8.58 mmol, 1.10 equiv), tert-butyl piperazine-1-carboxylate (1.45 g, 7.79 mmol, 1.00 equiv), 1,2-dichloroethane (20 mL). The mixture was stirred 30 min at room temperature. Sodium triacetoxyborohydride (4.96 g, 23.4 mmol, 3.01 equiv) was added. The resulting solution was stirred overnight at room temperature. The resulting mixture was washed with H2O (2×20 mL), dried over anhydrous sodium sulfate, filtered and concentrated under reduced pressure. The residue was chromatographed on a silica gel column with ethyl acetate/petroleum ether (1/4) to yield 2.50 g (77% yield) of tert-butyl 4-[[5-chloro-2-(pyrrolidin-1-yl)phenyl]methyl]piperazine-1-carboxylate as yellow oil. LCMS (ESI, m/z): 380 [M+H]+. The resulting solution was stirred overnight at room temperature The resulting mixture was washed with H2O (2×20 mL) dried over anhydrous sodium sulfate filtered concentrated under reduced pressure The residue was chromatographed on a silica gel column with ethyl acetate/petroleum ether (1/4)

Conditions: temp:100.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A 100 mL round-bottom flask was charged with 5-chloro-2-fluorobenzaldehyde (2.00 g, 12.6 mmol, 1.00 equiv), pyrrolidine (1.34 g, 18.8 mmol, 1.49 equiv), potassium carbonate (4.34 g, 31.4 mmol, 1.92 equiv), and dimethyl sulfoxide (10 mL). The resulting solution was stirred overnight at 100° C. in an oil bath and diluted with H2O (20 mL). The resulting solution was extracted with dichloromethane (3×20 mL) and the organic layers were combined, washed with H2O (3×10 mL), dried over anhydrous sodium sulfate, filtered and concentrated under reduced pressure. The residue was chromatographed on a silica gel column with ethyl acetate/petroleum ether (1/10) to yield 1.80 g (68% yield) of 5-chloro-2-(pyrrolidin-1-yl)benzaldehyde as brown oil. 1H NMR 300 MHz (CDCl3) δ 10.05 (s, 1H), 7.66 (d, J=2.4 Hz, 1H), 7.267-7.31 (m, 1H), 6.76 (d, J=9.0 Hz, 1H), 3.29-3.37 (m, 4H), 1.95-2.04 (m, 4H). LCMS (ESI, m/z): 210 [M+H]+. The resulting solution was extracted with dichloromethane (3×20 mL) washed with H2O (3×10 mL) dried over anhydrous sodium sulfate filtered concentrated under reduced pressure The residue was chromatographed on a silica gel column with ethyl acetate/petroleum ether (1/10)

Conditions: temp:100.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A 100 mL round-bottom flask was charged with 5-chloro-2-fluorobenzaldehyde (2.00 g, 12.6 mmol, 1.00 equiv), pyrrolidine (1.34 g, 18.8 mmol, 1.49 equiv), potassium carbonate (4.34 g, 31.4 mmol, 1.92 equiv), and dimethyl sulfoxide (10 mL). The resulting solution was stirred overnight at 100° C. in an oil bath and diluted with H2O (20 mL). The resulting solution was extracted with dichloromethane (3×20 mL) and the organic layers were combined, washed with H2O (3×10 mL), dried over anhydrous sodium sulfate, filtered and concentrated under reduced pressure. The residue was chromatographed on a silica gel column with ethyl acetate/petroleum ether (1/10) to yield 1.80 g (68% yield) of 5-chloro-2-(pyrrolidin-1-yl)benzaldehyde as brown oil. 1H NMR 300 MHz (CDCl3) δ 10.05 (s, 1H), 7.66 (d, J=2.4 Hz, 1H), 7.267-7.31 (m, 1H), 6.76 (d, J=9.0 Hz, 1H), 3.29-3.37 (m, 4H), 1.95-2.04 (m, 4H). LCMS (ESI, m/z): 210 [M+H]+. The resulting solution was extracted with dichloromethane (3×20 mL) washed with H2O (3×10 mL) dried over anhydrous sodium sulfate filtered concentrated under reduced pressure The residue was chromatographed on a silica gel column with ethyl acetate/petroleum ether (1/10)