Trimethylsilylacetylene → 6-Trimethylsilanylethynylbenzothiazol

Participants

Reaction Conditions

Reaction Steps

Trimethylsilylacetylene (106 ml), copper (I) iodide (0.948 g), and bis(triphenylphosphine) palladium(II) dichloride (1.75 g) were added to 6-bromobenzothiazole (53.3 g) in triethylamine (260 ml), and the mixture was stirred for 2.5 hours at 80° C. After the solvent was evaporated, the resultant residue was loaded on a short column (silica gel; hexane:ethyl acetate=2:1) for elution. The residue from the eluate was recrystallized from a mixed solvent of hexane-ethyl acetate, and consequently, 6-trimethylsilanylethynylbenzothiazole (20.0 g) was obtained as a colorless powder (mp: 104.5-105.0° C.). By repeated subjecting the filtrate to recrystallization repeated (n-hexhane-ethyl acetate), secondary crystals (12.1 g), tertiary crystals (9.68 g), and quaternary crystals (4.61 g) were obtained as a colorless powder.

Provenance & Evidence