Oxalyl chloride → HCID 59822488, compound

Participants

Reaction Conditions

Reaction Steps

To a solution of 1-isopropyl-5-methyl-2-oxo-1,2-dihydroquinoline-3-carboxylic acid (8.00 g, 32.6 mmol, step 4 in preparation 2) in dichloromethane (200 mL) was added dropwise oxalyl chloride (8.5 mL, 98 mmol) at 0° C. Then, N,N-dimethylformamide (3 drops) was carefully added to the mixture. The resulting mixture was stirred at 0° C. for 30 min and at room temperature for 3 h. Then, the mixture was evaporated in vacuo to give crude acid chloride as a yellow solid. Then, to a mixture of tert-butyl 4-(aminomethyl)piperidine-1-carboxylate (9.08 g, 42.4 mmol) and diisopropylethylamine (11.4 mL, 65.2 mmol) in dichloromethane (200 mL) was added dropwise a solution of crude acid chloride in dichloromethane (50 mL) at 0° C., and the mixture was stirred at room temperature for 3 h. The resulting mixture was poured onto water (300 mL), and the aqueous layer was extracted with dichloromethane (200 mL×3). The combined organic layer was dried over magnesium sulfate, and concentrated in vacuo. The residue was chromatographed on a column of silica gel with ethyl acetate/hexane (1/1.5) and then methanol/dichloromethane (1/40˜1/10) to give 15.0 g (quant.) of the title compound as a pale yellow solid.

Provenance & Evidence