Solid-phase synthesis of 7-acylamino-1,4-benzodiazepine-2,5-diones.
A method for the synthesis of polymer-bound 7-acylamino-benzodiazepine-2,5-diones is described. The amino group of an alpha-amino acid is linked to polystyrene or TentaGel resin via reductive amination of polymer-bound 4-alkoxy-2,6-dimethoxybenzaldehyde. Acylation with unprotected 5-nitroanthranilic acid is followed by base-catalyzed ring closure. Reduction of the nitro group yields enantiomerically pure 7-aminobenzodiazepin-2,5-dione attached via the N-4 atom to the resin. Acylation of the amino group on the aromatic ring with acid chlorides in N-methylpyrrolidone (no DMF, no base!) followed by cleavage from the resin using TFA/Me(2)S/water (90:5:5) provides the acylated benzodiazepinones in 52-69% (PS resin) and 41-48% (TG resin) yield (based on the theoretical loading) and >70% purity (HPLC, 210 nm). Using Fmoc-protected tyrosine fluoride in NMP gives the amino acid-coupled benzodiazepinones in 24% (PS resin) and 31% (TG resin) yield.
Ettmayer
Peter
P
Novartis Forschungsinstitut, Brunnerstrasse 59, Vienna A-1235, Austria. peter.ettmayer@pharm.novartis.com
Chloupek
Stefan
S
Weigand
Klaus
K
D001552:Benzazepines / Q000138:chemical synthesis* / Q000737:chemistry* / Q000302:isolation & purification / Q000494:pharmacology; D007073:Immunoglobulin E / Q000276:immunology; D015394:Molecular Structure
D001552:Benzazepines; D007073:Immunoglobulin E