6- „/-Methoxybenzyl-2 pyrazinone

For the solid-phase experiments [115], the commercially available Wang and HMPB-AM resins were chosen due their stability under the applied reaction conditions and an easy cleavage with TFA/DCM mixtures. Moreover, a novel, tailor-made and readily available linker, derived from inexpensive syringaldehyde was designed and proven to be superior to both standard Wang and HMPB-AM resins. For an initial study, as a proof of concept , the Wang linker was mimicked with a 4-methoxybenzyl group at N-1 position of a pyrazinone, and the sequence was evaluated in solution (Scheme 41). 

In contrast, l-benzyl-6-m-methoxybenzyl-2(l//)-pyrazinone gave only 6-m-mcihoxybcnzyl-2(l//)-pyrazinone on reductive debenzylation (liquid NHj—THF, Na 49%). ... 

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