SYNTHESIS METHOD OF OPTICALLY PURE ENANTIOMERS OF 5-ARYL SUBSTITUTED3-METHYL‑7- NITRO‑1,2-DIHYDRO‑3H‑1,4-BENZODIAZEPIN‑2-ONES

The aim of this work is to develop a simple, fast and efficient method for the synthesis optically pure enantiomers some 5-aryl-substituted 3-methyl‑7-nitro‑1,2-dihydro‑3H‑1,4-benzodiazepin‑2-ones using simple reagents. In course study, we found that interaction 2-amino‑5-nitrobenzophenone or 2-amino‑2’-chloro‑5-nitrobenzophenone with active L- D‑α-alanine N‑carboxyanhydrides in presence two equivalents trifluoroacetic acid does not leads formation corresponding reaction intermediates (2-amino-N-(2-benzoylphenyl)propanamide), even when refluxed 24 hours xylene. Acylation 5-nitro‑2-aminobenzophenones hydrochlorides chlorides, followed by cyclization under mild conditions, target characterized high optical purity. It noteworthy these reactions allow coupling chlorides derived from stereospecific α-alanines weakly reactive 5-nitro derivatives 2-aminobenzophenone without racemization. important note chloride α-alanines, which are chemically unstable extremely sensitive moisture, used as building blocks work. case, individual antipodes were synthesized absolute chloroform phosphorus pentachloride products isolated filtration precipitates, applying additional purification them. structure title compound was confirmed spectroscopy 1H 13C NMR, FAB mass spectrometry methods, purity controlled HPLC. To analyze the1,2-dihydro‑3H‑1,4-benzodiazepines work, HPLC applied stationary chiral phase CiraDex®. This preparation potential practical importance design various 3-alkyl 1,2-dihydro‑3H‑1,4-benzodiazepin‑2-ones wide spectrum biological activity.