title: Solid-supported solution-phase synthesis of 4-amino-1,2,4,5-tetrahydro-2-benzazepine-3-ones.
abstract: Starting from Boc-o-aminomethylphenylalanine, a solution-phase parallel synthesis of 2,4-substituted 4-amino-1,2,4,5-tetrahydro-2-benzazepine-3-ones is described. This heterocycle has two nitrogen functions, which are differentiated and can be selectively substituted. The sources of diversity are aldehydes for the R(1) position and carboxylic acids, sulfonyl chlorides, or isocyanates for the R(2) position. High-throughput synthesis and purification of this multistep synthetic sequence was accomplished using polymer-bound reagents and scavengers and liquid-liquid extraction protocols, and a small library of compounds was prepared. Polymer-bound cyanoborohydride was found to work well for the reductive amination. Scavenging of excess of amine was performed by polymer-bound benzaldehyde, and cyclization was performed in the presence of polymer-bound coupling reagent 1-ethyl-3-(3-dimethylaminopropyl)-carbodiimide (EDC). After Boc-deprotection, the second nitrogen can be acylated using carboxylic acids, sulfonylated or converted to a urea. The acylation is again performed by polymer-bound EDC. Excellent yields and purities were obtained.
authors.affiliation: Organic Chemistry Department, Vrije Universiteit Brussel, Pleinlaan 2, B-1050 Brussels, Belgium.
authors.forename: Isabelle
authors.initials: I
authors.lastname: Van den Eynde
authors.forename: Karolien
authors.initials: K
authors.lastname: Van Rompaey
authors.forename: Francesco
authors.initials: F
authors.lastname: Lazzaro
authors.forename: Dirk
authors.initials: D
authors.lastname: Tourwé
mesh_terms: D000447:Aldehydes; D000577:Amides / Q000737:chemistry; D000586:Amination; D001552:Benzazepines / Q000138:chemical synthesis* / Q000737:chemistry*; D006900:Hydroxylation; D015394:Molecular Structure; D012996:Solutions; D013455:Sulfur / Q000737:chemistry
chemical_list: D000447:Aldehydes; D000577:Amides; D001552:Benzazepines; D012996:Solutions; D013455:Sulfur