Figure 1. A Synthesis For the Reaction of 1,8-diamino-3,6-dithiaoctane
Synthesis of Dithianamines
It is the purpose of this work to synthesize the three thioether ligands shown in Table 1. Those ligands will be used in the synthesis of cobalt(III) complexes
Table 1. Proposed Ligands |
N H 2CH 2CH 2SCH(CH 3)(CH 3)CHSCH 2CH 2NH 2 (abbreviated EBE for ethyl-butyl-ethyl) |
N H 2CH 2CH 2SCH 2CH 2CH 2SCH 2CH 2NH 2 (abbreviated ETE or EPE for ethyl-propyl ethyl) |
N H 2CH 2CH 2CH 2SCH 2CH 2SCH 2CH 2CH 2NH 2 (abbreviated TET or PEP for propyl-ethyl-propyl) |
In the literature is described a general synthesis of NSSN ligands that involves reaction of an n-bromoalkylphthalamide with a dithiol in the presence of a strong base; the phthalamide rings are then opened with hydrazine and the ligand itself is extracted into ether following treatment with a strong base such as solid sodium or potassium hydroxide. Worrell and Busch, for example, synthesized 1,8-diamino-3,6-dithiaoctane by reacting bromoethylphthalamide with 1,2-ethanedithiol in sodium ethoxide, as shown in figure 1.
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Figure 1. A Synthesis For the Reaction of 1,8-diamino-3,6-dithiaoctane |
Therefore, ETE was synthesized by reacting bromoethylphthalamide with 1,3-propanedithiol, and TET was synthesized by reacting bromopropylphthalamide with ethanedithiol. In a similar fashion, the proposed ligand EBE could be synthesized by reacting 2,3-butanedithiol (which is a commercially available reagent) with bromoethylphthalamide. Initial small-scale investigation suggests this reaction is possible, yielding a mixture of products, as shown in figure 2.
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Figure 2. A Synthesis For the Reaction of 1,8-diamino-3,6-dithiaoctane |
