Solid-Phase Synthesis of Aminothiazoles

Significance

An efficient approach for the parallel synthesis of aminothiazoles was described. The synthesis started from 4-methoxybenzhydryl­amino resin (MBHA resin) bound acylated amino acids 1 (loading: 1.1 mmol/g). Reduction of the amide groups with BH₃˙THF afforded the resin-bound diamines 2. Treatment of 2 with Fmoc isothiocyanate followed by removal of the Fmoc group led to the corresponding dithioureas 3. The resin-bound dithioureas 3 were treated with a variety of α-halo ketones to give the resin-bound diaminothiazoles 4, which released the desired ­diaminothiazoles 5 in 80-90% yield and 82-94% purity.