SES-chloride has been obtained in higher yield and purity by improving Weinreb's original procedure, allowing efficient access to the primary SES-amide. Linear triamines can be built conveniently from the SES-amide in high yields, with the potential for orthogonal protection. The modified Richman-Atkins cyclisation of SES-amides allows access to novel biologically interesting triazamacrocycles with combinations of three-, four-, five- and six-carbon bridges within the ring. Purification of the free macrocyclic amines by distillation greatly simplifies the workup, increasing the practicability of multi-gram scale synthesis. Although CsF sometimes provided undesirably low yields in the deprotection step, alternative fluoride sources were found to be unsuitable for the deprotection of SES-triazamacrocycles.
- Protecting groups