Acetic Acid → 1,1-Dimethylethyl 4-(2-thiazolylamino)-1-piperidinecarboxylate

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Reaction Steps

A mixture of 5.0 g (50 mmol) 2-aminothiazole, 10.0 g (50 mmol) tert-butyl 4-aminopiperidine-1-carboxylate, 21.2 g (100 mmol) sodium triacetoxyborohydride and 5.7 ml (100 mmol) acetic acid in THF (100 ml) was stirred for 24 h at RT. Subsequently, a further 10.6 g (50 mmol) sodium triacetoxyborohydride and 2.85 ml (50 mmol) acetic acid were added and stirring took place for a further 2 d at RT. The solvent was removed in vacuo and the residue was taken up by chloroform and washed a plurality of times with 10% aq. NaOH soln and water. The organic phase was dried over MgSO4, filtered, and concentrated in vacuo. Column chromatography (SiO2, Chloroform/EtOH 20:1) was carried out on the residue, yielding 712 mg (2.5 mmol, 25%) tert-butyl-4-(thiazol-2-ylamino)piperidine-1-carboxylate.

Provenance & Evidence