3-Methylisothiazole → 3-Methyl-5-(tributylstannyl)isothiazole

Temperature

-78 °C

To a cold (−78° C.) solution of 3-methylisothiazole (100 mg, 1.0 mmol) in anhydrous THF (2.0 mL) was added n-butyllithium (0.693 mL, 1.1 mmol) dropwise. After stirring for 60 min at −78° C., a solution of tributylchlorostannane (0.326 mL, 1.210 mmol) in anhydrous THF (0.5 mL) was added to the reaction mixture. The reaction mixture was stirred for 30 min at −78° C. and then allowed to warm to RT over a 2 to 3 h period. Saturated aq NaHCO3 was added and the aqueous phase was extracted with EtOAc (3×50 mL). The combined organic phase was dried over anhydrous Na2SO4, filtered, and evaporated in vacuo. The residue was purified by silica gel column chromatography (9:1 Hexane/EtOAc, Flash 60 column) to give the title compound. 1H NMR (500 MHz, CDCl3) δ ppm 0.86-0.94 (m, 9 H), 1.05-1.21 (m, 6 H), 1.26-1.38 (m, 6 H), 1.44-1.65 (m, 6 H), 2.56 (s, 3 H), 6.97-7.04 (m, 1 H).

1. stirringThe reaction mixture was stirred for 30 min at −78° C.
2. temperatureto warm to RT over a 2 to 3 h period
3. extractionthe aqueous phase was extracted with EtOAc (3×50 mL)
4. dry with materialThe combined organic phase was dried over anhydrous Na2SO4
5. filtrationfiltered
6. customevaporated in vacuo
7. customThe residue was purified by silica gel column chromatography (9:1 Hexane/EtOAc, Flash 60 column)

ORD record

ord-8021591bc564447a87c29f93ee468254

Source dataset

uspto-grants-2015_08

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US09108970B2