Studies in Chlorin Chemistry. III. A Practical Synthesis of CD-Ring Symmetric Chlorins of Potential Utility in Photodynamic Therapy

摘要

C,D-Ring symmetric chlorins >8 were prepared in 47-85% yield, on scales up to several hundred milligrams, by condensation of appropriately substituted bis-formyldihydro-dipyrrins >6 and dihydropyrromethane bis-carboxylic acids >7 in 5% TFA/CH2Cl2 (25 examples). Target chlorins were chosen to systematically probe the effect of lipophilic and hydrophilic substituents on tissue partitioning and cellular membrane penetration in photodynamic therapy (PDT).