Solid-phase synthesis of 3,4-dihydro-benzo[e][1,4]diazepin-5-ones with three diversity positions is described. Various primary amines were used as the starting material and immobilized on the polystyrene resin equipped with different acid-labile linkers. Polymer-supported amines were converted to α-aminoketones with the use of their sulfonylation with the 4-nitrobenzensulfonylchoride (4-Nos-Cl) and subsequent alkylation with α-bromoketones. After the cleavage of the 4-Nos group, the corresponding α-aminoketones were acylated with various o-nitrobenzoic acids. Reduction of the nitro group followed by spontaneous on-resin ring closure gave the target immobilized benzodiazepines. After acid-mediated cleavage the products were obtained in very good crude purity and satisfactory yields, which makes the developed method applicable for simple library synthesis of the corresponding derivatives in a combinatorial fashion.

Department of Organic Chemistry Institute of Molecular and Translational Medicine Faculty of Science Palacky University Olomouc Czech Republic

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Synthesis of chiral 1,4-oxazepane-5-carboxylic acids from polymer-supported homoserine