Base-promoted formal arylation of benzo[d]oxazoles with acyl chloride.

A base-promoted formal arylation of benzo[d]oxazoles with acyl chloride was achieved in moderate to good yields. This reaction was triggered by the N-acylation of oxazole to form an iminium intermediate. Then, the addition of H2O to the iminium formed the hemiacetal intermediate. After the sequential ring-opening, extrusion of CO, the ring closure, the dehydration delivered the formal arylation product. In comparison with the transition-metal-catalyzed methodology, it represents an alternative arylation method leading to 2-arylbenzooxazole.