... Heterocyclic Chem., 30, 1533 (1993). ... 2,3-b]quinoline 4 and 4-(2- chloroethyl)-2,3-dihydropyrido[ 2,3-ò][l,4]oxazine 5 (Figure 2). To the best of our knowledge, no reports for the prepa- ration of these substituted heterocycles exist in ... [6] M. Harfenist, A. Barley and W. Alazier, J. Org. ...