Mustard-based prodrug

The potential utility of o-nitrobenzyl as a photocleavable nitrogen protecting group for indoles, benzimidazole and 6-chlorouracil has been evaluated. Simple photolyses of the protected molecules at 300 nm afford good yields of the starting materials. Nitrobenzyl-based phosphoramide mustards (94) with various substituents (R, R, R ) have been developed as potential prodrugs for cancer therapy. UV and P NMR spectroscopy showed that the phosphoramide mustard was quickly liberated upon irradiation with mercury arc lamps. 2-Nitro-benzyl quaternary ammonium derivatives of norbutyrylcholine (A,iV-dimethyla-minoethyl butyrate) have been synthesized and assessed as photolabile inhibitors... 

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