3-Methyl-isothiazole → 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 minutes 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 minutes at −78° C. and then allowed to warm to RT over a 2 to 3 hour 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 chromatography (Flash 60 column) eluting with hexane/EtOAc (9:1) to give the title compound. 1H NMR (500 MHz, CDCl3) δ ppm 0.86-0.94 (m, 9H), 1.05-1.21 (m, 6H), 1.26-1.38 (m, 6H), 1.44-1.65 (m, 6H), 2.56 (s, 3H), 6.97-7.04 (m, 1H).

1. stirringThe reaction mixture was stirred for 30 minutes at −78° C.
2. temperatureto warm to RT over a 2 to 3 hour 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 chromatography (Flash 60 column)
8. washeluting with hexane/EtOAc (9:1)

ORD record

ord-84db893baa034f19b6c280008b416011

Source dataset

uspto-grants-2015_06

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US09056873B2