Design, synthesis and characterization of 3-alkyl substituted chlorin derivatives

Bing Cun Cui, Xin Yu, Dong Mei

Abstract

The novel 3-alkyl substituted chlorin derivatives exhibiting good lipophilicity were obtained from methyl pheophorbide-a by modification of the peripheral functional groups. The vinyl group at 3-position was oxidized with OsO4 and NaIO4 to form the formyl group and the Grignard reaction of this aldehyde with the alkyl magnesium bromide was carried out to give the corresponding 3-(1-hydrroxylalkyl) pheophorbide-a. The 3-(1-hydrroxylalkyl) functional group was converted into 3-alkyl chain by dehydration and hydrogenation. The Qy band of prepared photosensitizers were affected by the substituent on the Qy axis ( N21-N23). The structures of new photosensitizers were characterized by elemental analysis, UV-vis and 1H NMR spectra