Quinazolines et benzodiazépines-1, 4. LVI. Oxadiazolo-1, 2, 4[4, 5-d] benzodiazépines-1, 4: synthése et passage aux oxazolo [3, 2-d] benzodiazépines-1, 4

The tricyclic derivatives 4–14 can be prepared by 1, 3-dipolarcycloaddition of the appropriate nitrile oxides on the corresponding 1, 4-benzodiazepines. NaBH⁴ reduction of the esters 12–14 was found to proceed very readily; starting from 13 it is possible, by proper reaction conditions, to get in good yield either the monoalcohol 19 or the aminodiol 20 . The alcohols 19 and 23 undergo an acid-catalysed rearrangement which produces the amidoximes 24 and 26 . The determination of the structure of 24 by X-ray diffraction analysis is also presented.