Synthesis of 20-meso-Substituted Chlorins with the Basic Skeleton of Chlorophyll-a

Lumin Wang, Zhen Wang, Ze Yang, Yingxue Jin, Jinjun Wang
2012 Youji huaxue  
Methyl pheophorbide-a (MPa) was used as starting material. The coupling reaction of MPa with diazobenzene hydrochloride, hydrobromide and sulfate was carried out to give traces of expected product, while major products were 20-halogenated and nitroso-substituted chlorins. Zinc methyl pyropheophorbide-a reacted with 3-N,N-dimethylacrolein to give Vilsmeier product. The bromination of pyropheophorbide-d with N-bromosuccinimide (NBS) formed single 20-brominated product, the vinyl group of which
more » ... l group of which was resumed by Wittig reaction to give 20-bromopyropheophorbide-a. The electrophilic substitution of other chlorphyllous degradation products afforded corresponding 20-meso-substituted chlorin derivatives in better yields, respectively. The structures of all the new chlorins with basic skeleton of chlorophyll were characterized by UV, IR, 1 H NMR spectra and elemental analysis.
doi:10.6023/cjoc1201202 fatcat:ufiivtuplnf75exngjkputnkru