Syntheses Of Diazadithiacrown Ethers Containing Two 8-Hydroxyquinoline Side Arms

Ten new diazadithiacrown ethers containing two 8-hydroxyquinoline (HQ) sidearms attached through the HQ 7-positions and four new diazadithiacrown ethers containing two HQ sidearms attached through the HQ 2-positions have been prepared. Some of these new ligands also contain a hydroxymethyl substituent. The starting macrocyclic diazadithiacrown ethers were obtained by treatment of a bis(a-chloroamide) with the appropriate dimercaptan using K2CO3 as the base followed by reduction of the resulting macrocyclic dithiadiamide by BH3-THF or by NaBH4 in the presence of BF3-ether as a catalyst. HQ-containing ligands 23-32 were synthesized by a Mannich reaction of the secondary macrocyclic diamines with the substituted-8-hydroxyquinoline. HQ-containing ligands 33-36 were prepared by reductive amination of the secondary macrocyclic diamines with 8-hydroxyquinoline-2-carbaldehyde. The HQ-containing diazadithiacrown ethers which also contain a hydroxymethyl group on the macroring (23-29, 33, and 35) are more soluble in polar solvents than those without the hydroxymethyl group.