Potential histamine H2-receptor antagonists. Synthesis, structure and activity of a few open models related to classical H2-antagonists.

A few ethers and oximes structurally related to classical H2-antagonists have been synthetized and tested for their in vitro H2-antagonist activity. The compounds in which cyclic "urea equivalent" groups are joined to a cyclohexylmethyl moiety showed a high increase of activity in comparison with the unsubstituted analogues. This finding supports the hypothesis of the existence of an accessorial binding area on H2-receptor near the site fitted by cyclic "urea equivalent" groups.