Hydrochloric Acid → 1-(5-Bromo-7-pyridin-2-yl-benzothiazol-2-yl)-3-ethyl-urea

Participants

Reaction Conditions

Reaction Steps

A stirred mixture of the 1-(5,7-dibromo-benzothiazol-2-yl-3-ethyl urea (2.62 g, 0.00687 mol) and Dichlorobis(triphenylphosphine)-palladium (0.48 g 0.000687 mol), under nitrogen, was treated in one portion, via a syringe, with 2-pyridyl zinc bromide solution (0.5M solution in THF, 7.66 g, 0.0344 mol). The reaction mixture was heated, with stirring, at 55° C. for 18 hours, allowed to cool and poured into 500 ml of water containing ˜5 ml of conc hydrochloric acid. The suspension was stirred and the solid filtered off, washed with water, followed by 20 ml of 1:1 DCM/Methanol mixture to give the crude 1-(5-Bromo-7-pyridin-2-yl-benzothiazol-2-yl)-3-ethyl-urea (1.43 g). This was purified by “flash” silica chromatography using 0 to 100% hexane/ethyl acetate followed by 0 to 100% methanol in ethyl acetate to elute the required product as a beige solid (1.1 g).

Provenance & Evidence