A simple synthesis of Δ2-oxazolines, Δ2-oxazines, Δ2-thiazolines and 2-substituted benzoxazoles

Article abstract of DOI:10.1016/0040-4020(93)80021-K

Carboxylic acids react readily at 0° ← + 24°C with amino alcohols, amino mercaptans and o-aminophenols in the presence of triphenylphosphine- or tributylphosphine dichloride (generated in situ from the reaction of the phosphines with hexacholoroethane or CCl₄) and triethylamine in acetonitrile to form the corresponding Δ²-oxazolines, Δ²-oxazines, Δ²-thiazolines and 2-substituted benzoxazoles in one reaction step in yields of up to 80%.