| 摘要 |
Compounds of the formula: <CHEM> wherein: R, R<1> and R<2> are, e.g., hydrogen; <CHEM> where X and Y taken together are, e.g., -CH2-CH2-; R<4> is, e.g., hydrogen; and n is 1 to 3; or R<2> is &lparstr& CH2 &rparstr& @B &lparstr& CH2 &rparstr& @NR<7>R<1><5> where r and s are independently 0 to 3; B is, e.g., absent or -O-; <CHEM> where R<9> is, e.g., loweralkyl; i |
