306775-52-0

Upstream product

• 20443-98-5 2,6-Dichlorobenzyl bromide 
• 40298-69-9 4-(2,6-dichlorobenzyloxy)-L-phenylalanine 
• 60-18-4 L-tyrosine 
• 27532-96-3 glycine tert-butyl ester hydrochloride 
• 306775-51-9 (S)-N^α-phthaloyl-O-(2,6-dichlorobenzyl)tyrosine 

Downstream Products

• 306775-54-2 3-[2(S)-(1,3-dihydro-1,3-dioxo-2H-isoindol-2-yl)-3-(4-(2,6-dichlorobenzyloxyphenyl))propanoyl]-5-oxazolidinone 
• 306775-53-1 (S)-N^α-phthaloyl-O-2,6-dichlorobenzyltyrosinylglycine 

Relevant academic research and scientific papers

Efficient synthesis of (S)-4-phthalimido-1,3,4,5-tetrahydro-8-(2,6-dichlorobenzyloxy)-3-oxo-2H-2-ben zazepin-2-acetic acid (Pht-Hba(2,6,Cl2-Bn)-Gly-OH)

4-Amino-2-benzazepin-3-ones have proven very useful for studying the biologically active conformations of peptides. The synthesis of Pht-Aba-Xaa-OH by reaction of the corresponding 1,3-oxazolidin-5-one with trifluoromethanesulfonic acid (TFMSA) has been reported in the literature. However, when this procedure was applied to the preparation of Pht-Hba(Bn)-Gly-OH 8, many byproducts were formed and the yield of the desired aminobenzazepinones 7 and 8 was very low. We report in this paper an efficient methodology for the synthesis of Pht-Hba(2,6-Cl2-Bn)-Gly-OH 17 starting from the commercially available tyrosine. In our procedure, the dipeptide Pht-Tyr(2,6-Cl2-Bn)-Gly-OH 15 is converted to the 1,3-oxazolidin-5-one 16 which then undergoes Friedel-Crafts cyclization in the presence of tin tetrachloride to afford the desired 4-phthalimido-1,3,4,5-tetrahydro-8-(2,6-dichlorobenzyloxy)-2-benzazepin-3-one 17 in excellent yield.