Combinatorial synthesis of chemical building blocks 1. Azomethines.

128 Azomethines were synthesized through condensation of carbonyl compounds with various amines in pyridine in the presence of Me(3)SiCl as promoter and water scavenger in 58-98 % yield. Et(3)N was added to reaction mixtures before precipitating the product with H(2)O to prevent acid catalyzed hydrolysis of the C=N bond. The scope and limitation of the method are discussed. High yields and simple setup/workup procedure make this method suitable for the combinatorial synthesis of azomethines, which are suitable as starting materials for high throughput synthesis of various combinatorial libraries. The azomethines synthesized were used as starting materials in a one-pot combinatorial synthesis of amines and amides.