1516 Journal of Medicinal Chemistry, 1977, Vol. 20, No. 11 and Mr. L. Cornwell for helpful suggestions in the preparation of this manuscript. References and Notes Notes 19, 1148 (1976). (2) E. F. Godefroi, J. Van Cutsem, C. A. M. Van der Eycken, and P. A. J. Janssen, J. Med. ...