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Reagents: (i) H2N-CH2-Y-(X-CH2CH2)n-NH2, (C2H5)3N, CH2Cl2. (ii) H2N-CH2-Y-(X-CH2CH2)n-NH-COOC(CH3)3, CH2Cl2, (C2H5)3N. (iii) CF3COOH. (iv) CH2Cl2, (C2H5)3N. (v) N-methylpiperazine. Spacers: 3a and 9a: Y = (CH2)2, X = CH2, and n = 1; 3b and 9b: Y = (CH2)3, X = CH2, and n = 1; 3c and 9c: Y = CH2, X = CH2, and n = 2; 3d and 9d: Y = CH2, X = O, and n = 2; 3e, 8e, and 9e: Y = CH2, X = O, and n = 7; 3f, 8f, and 9f: Y = CH2, X = O, and n = 9.
