Bifunctional Cytotoxic DNA Crosslinking Agents

Kamal et al, US Patent 7,015,215 (March 21, 2006) Assignee Council of Scientific and Industrial Research (Hyderabad, India) Utility Versatile Antineoplastic Agents 

Preparation of (2S)-/V-[4-(2-bromoethoxy)-5-methoxy-2-nitrobenzoyl]pyrro-lidine-2-carboxaldehyde diethyl thioacetal 

A mixture consisting of (2.S )-/V-(4-hydroxy-5-mc(hoxy-2-ntirobcnzoyl)pyrrolidinc-2-carboxaldehyde diethylthioacetal (2 mmol), 1,2-dibromoethane (2.5 mmol), and K2C03 (3 mmol) dissolved in 40 ml acetone was refluxed 48 hours, then poured into water, and extracted with EtOAc. The solution was concentrated, the residue purified using chromatography with silica gel using EtOAc/hexane, 1 1, and the product isolated. 

Preparation of l,l - [(bisethane-l,A-diyl)piperazine]dioxy bis[(llaS)-7-methoxy-2-nitro-benzoylpyrrolidin-2-carboxaldehyde diethylthioacetal] 

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