Oxalyl chloride → tert-Butyl 4-(4-chlorocarbonylphenyl)-3-[4-(3-methoxypropyl)-3-oxo-3,4-dihydro-2H-benzo[1,4]oxazin-6-ylmethoxy]piperidine-1-carboxylate

Participants

Reaction Steps

0.190 ml of oxalyl chloride are added dropwise to a solution of 0.600 g of tert-butyl 4-(4-carboxyphenyl)-3-[4-(3-methoxypropyl)-3-oxo-3,4-dihydro-2H-benzo[1,4]oxazin-6-ylmethoxy]piperidine-1-carboxylate in 6 ml of dichloromethane. The reaction solution is subsequently stirred at room temperature over 1 hour and then admixed with 2 drops of N,N-dimethylformamide and stirred at room temperature for a further 35 minutes. The reaction mixture is concentrated by evaporation to dryness and used further as the crude product without purification. Reddish oil, Rt=5.50.

Provenance & Evidence