2-Chloro-3-(4-chlorooxazole-5-yl)-indoles and 4-chloro-5-phenyl-oxazoles 3 were synthesised from acyl cyanides 1, aldehydes 2 and hydrogen chloride. By further derivatisation of the substituent at position 2 of the 4-chlorooxazole ring, useful potential building blocks 3l, 3n and 3o for a total synthesis of diazonamide A, were obtained.