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The synthesis and biological evaluation as potential CCK‐B receptor ligands of a number of 1‐isopentyl‐3‐aryloxycarbamoyl‐5‐aryl‐1,5‐benzodiazepines substituted with halogen atoms on the benzo‐fused ring is here briefly discussed.

A series of 5-phenyl-3-ureidobenzodiazepine-2,4-diones was synthesized and evaluated as cholecystokinin-B (CCK-B) receptor antagonists. Structure-activity relationship (SAR) studies revealed the importance of the N-1 substituent for potent and selective CCK-B affinity. Addition of substituents at the urea side chain provided in some cases more potent compounds. Moreover the introduction of bulky substituents such as adamantylmethyl at N-1 and resolution of the racemic ureas resulted in our lead compound GV150013.

Exposure of a cyclic a-diazo-P-hydroxy ester to different concentrations of boron trifluoride in various solvents affords an interesting variety of products.Diazo-hydroxy-acylmethanes 3a,b, easily prepared by aldoltype condensation of lithio-diazo-acylmethanes 2 with aldehydes and ketones la,b, are valuable synthetic intermediates able to undergo a range of transformations.1-16 It was shown, for example, that 3a,b rearrange by proton acid catalysis or thermolysis with carbon or hydrogen migrati0n.2,~?5 The subsequent discovery that the transformation can be achieved smoothly in almost quantitative yield by exposing 3a,b to catalytic amounts of dirhodium(I1) tetraacetateg has been exploited to obtain synthetic intermediates which are difficult to obtain by other means.17-20 The possibility that 3a,b may be smoothly converted into the corresponding P-hydroxycarbony1 compounds by catalytic hydrogenation (PdC) has also been exploited synthetically. 16 The little studied Lewis-acid catalysed decomposition of a-diazo-6-hydroxy ketones or esters has been reported to follow a different path. Thus, when exposed to boron trifluoride-diethyl ether in a polar solvent such as acetonitrile, the acyclic compounds 3a (R' = H) give the corresponding acylacetylenes 6 as major products along with minor amounts of migration products.3.779J4 The

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