Sodium Carbonate → 2-(1H-pyrazol-4-yl)-1,3-thiazole

Temperature

70 °C

To a solution of 2-bromothiazole (1 g, 6 mmol) in toluene (20 mL) and ethanol (10 mL) was added 4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-1H-pyrazole (1.41 g, 7.3 mmol), 2 M sodium carbonate solution (17.3 mL) and Pd(PPh3)4 (7 mg, 0.06 mmol). The reaction mixture was purged with argon for 15 min. The resulting mixture was heated at 70° C. for 4 h. The reaction mixture was concentrated and diluted with water (100 mL), extracted with ethyl acetate (2×200 mL). The combined extracts were washed with brine solution (20 mL), the organic solvent was dried over Na2SO4, filtered and concentrated under reduced pressure to obtain crude product. The crude product was purified by flash chromatography (60-120μ; 50% ethyl acetate in hexane) to afford racemic 2-(1H-pyrazol-4-yl)thiazole as brown liquid (520 mg, 56% yield). 1H NMR (400 MHz, DMSO-d6): δ 13.22 (br s, 1H), 8.30 (s, 1H), 7.93 (s, 1H), 7.73 (s, 1H), 7.55 (d, 1H); LC-MS m/z calculated for [M+H]+152.02, found 152.1.

1. customThe reaction mixture was purged with argon for 15 min
2. concentrationThe reaction mixture was concentrated
3. additiondiluted with water (100 mL)
4. extractionextracted with ethyl acetate (2×200 mL)
5. washThe combined extracts were washed with brine solution (20 mL)
6. dry with materialthe organic solvent was dried over Na2SO4
7. filtrationfiltered
8. concentrationconcentrated under reduced pressure
9. customto obtain crude product
10. customThe crude product was purified by flash chromatography (60-120μ; 50% ethyl acetate in hexane)

ORD record

ord-9dc7be69b9d54fdf8c4089f2bf0bd793

Source dataset

uspto-grants-2014_08

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08809372B2