2-Chlorothiazole → 1-(2-Chlorothiazol-5-yl)ethanone

Temperature

25 °C

A solution of 2-chlorothiazole (2.5 g, 21 mmol) in THF (10 mL) was added dropwise to a chilled (−75° C.) 2.5 M hexanes solution of n-BuLi (9.2 mL, 23 mmol) in THF (70 mL). After the addition was complete the reaction mixture was stirred for 1 hr. Then a solution of N-methoxy-N-methylacetamide (2.4 g, 23 mmol) in THF (5 mL) was added. The reaction was allowed to stir overnight while warming to 25° C. The reaction was diluted with H2O and thrice extracted with ethyl ether. The organic portions were combined, washed with brine and then dried (Na2SO4). Filtration and removal of solvent gave a residue that was purified by flash chromatography on silica eluting with 5 percent Et2O in pentane, affording product as a white solid, 2.5 g, 15.5 mmol, 73 percent yield.

1. additionAfter the addition
2. stirringto stir overnight
3. extractionextracted with ethyl ether
4. washwashed with brine
5. dry with materialdried (Na2SO4)
6. filtrationFiltration and removal of solvent
7. customgave a residue that
8. customwas purified by flash chromatography on silica eluting with 5 percent Et2O in pentane
9. customaffording product as a white solid, 2.5 g, 15.5 mmol, 73 percent yield

ORD record

ord-3e95e4c4c79240cb8344f791c8b89da2

Source dataset

uspto-grants-2009_05

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07531482B2