Benzodiazepines show a broad spectrum of biological activities. In an ongoing effort to extend molecular diversity in this type of systems, we developed a strategy for synthesizing3,4‐dihydro‐1H‐pyrido[2,3‐e][1,4]diazepine‐2,5‐dione compounds starting from 2‐hydroxynicotinic acid and by using an Ugi reaction as a key step in the synthesis. We opted to use 2‐isocyanophenyl benzoate instead of Armstrong's convertible isocyanide in this multicomponent reaction.

The development of a multigram synthesis of the orthogonally protected amino acid-derived Phaol [2-{[(2S)-2-amino-3-phenylpropyl]amino}ethanol] is described. The goal of this work is to synthesize an orthogonally protected Phaol in a multigram scale up to 10 g (Cbz-Phaol), so it can be used in solution-based peptide synthesis of peptaibols. Two synthetic schemes were proposed and examined. Between the reduction-coupling and the coupling-reduction scheme, the latter gave the best results. A two-step synthesis affords easily purifiable products. Several analogs were synthesized using this methodology. All the molecules were orthogonally protected, so that they can be used in peptide synthesis. Deprotection posed no problems.

Synthesis of the title compounds is achieved using the Ugi multicomponent reaction as key step.

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