Oxalyl chloride → HCID 81430882, compound

Participants

Reaction Conditions

Reaction Steps

(I4B): Anhydrous DMF (242 ml) was cooled to −20° C. in a dry ice/acetone bath and the internal temperature was monitored carefully and maintained at or below this temperature. Neat oxalyl chloride (9.51 ml, 109 mmol) was then slowly added dropwise via addition funnel and the vessel was properly vented to allow the escape of gases generated. Following the addition, the cloudy-white suspension was stirred at −20° C. for 30 min. A solution containing methyl 3-bromo-4-hydroxy-5-nitrobenzoate (10 g, 36.2 mmol) in DMF (121 ml) was then added slowly, not allowing the internal temp to exceed −10° C. Following the addition, the suspension was warmed to rt and then heated to 100° C. for 2 h. The reaction was cooled to rt and stirred over weekend. The dark brown solution was poured into ice water and diluted with EtOAc. The aqueous phase was extracted twice with EtOAc. The combined organics were washed with water and brine, then dried over anhydrous sodium sulfate. Filtration and concentration afforded methyl 3-bromo-4-chloro-5-nitrobenzoate (10 g) as a yellow solid that was dried in vacuo overnight.

Provenance & Evidence