Abstract 5-Ethoxyoxazoles or 2-acylamino propanoates were synthesized by aza-Wittig reaction of iminophosphorane with acyl chloride in the presence of triethylamine. Reactions of 5-alkoxyoxazole with triphenyphosphine produced iminophosphoranes. A tandem aza- Wittig reaction of iminophosphorane with isocyanate or carbon disulfide generated oxazolo [3, 2-c] quinazolines in satisfactory yields.
