Synthesis of a thiazole library using liquid- and solid-phase extractions

Synthesis of a thiazole library using liquid- and solid-phase extractions 

The excess of 34 was trapped either with A (4-carboxyphenyl)thiourea (36) yielding 37 and removed by LPE, or with polymer-bound thiouronium salt 38 to yield polymer-bound imidazole 39 (in analogy to a liquid-phase strategy developed by Dodson et al. ) and removed by SPE. Subsequent treatment of thiazoles 35 with a series of amino acid-derived isocyanates 40 gave the second generation of thiazoles 41 in essentially quantitative yields. Excess of 40 was trapped with 

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