Synthesis and crystal structure of 2‐phosphonoalkyl‐1, 2‐benzisoselenazol‐3(2H)‐ones and their antitumor activities

The title compounds were synthesized in good yields by the condensation reaction of diphenyl α‐aminoalkylphosphonates with 2‐(chloroseleno)‐benzoyl chloride. Their structures were confirmed by spectroscopic methods and microanalyses. The X‐ray analyses showed that the selenium‐containing fused ring has a planar structure and that, by the molecular packing of the unit cells, two adjacent molecules are symmetrically linked to each other through Se(1c) … O=P(1) bonding interactions with an intermolecular Se(1c) … O distance of 2.797 Å. The results of bioassay indicated that some of these compounds possess potent antitumor activities against some human carcinoma cells in vitro. © 1999 John Wiley & Sons, Inc. Heteroatom Chem 10:247–254, 1999