Potassium Carbonate → 4,5-diiodo-2-cyclopropyl-1-methyl-1H-imidazole

Temperatur

75 °C

4-Iodo-2-cyclopropyl-1-methyl-1H-imidazole, 5k′. To a solution of 2-cyclopropyl-1-methyl-1H-imidazole (4a) (5.5 g, 45.0 mmol) in isopropyl acetate (110 mL) was added K2CO3 (1.25 g, 9.0 mmol) followed by NIS (40.3 g, 179.1 mmol) in portions over 2 h. The solution was stirred at 75° C. for 3 h, allowed to cool to room temperature and quenched with a 10% aqueous solution of K2CO3. The organic layer was washed with 10% K2CO3. The combined organic layers were concentrated affording crude 4,5-diiodo-2-cyclopropyl-1-methyl-1H-imidazole (10.5 g) as a dark solid. A solution of the resulting solid in THF (100 mL) was cooled to −20° C. and treated with 2 M i-PrMgCl in THF (17.5 mL, 35.0 mmol) dropwise. The reaction mixture was quenched with water and filtered. The organic layer was washed with brine and water, and concentrated afford 5k′ (8.64 g, 77% yield) as a dark orange oil. 1H-NMR (400 MHz, CDCl3) δ 6.85 (s, 1H), 3.66 (s, 3H), 1.74 (dt, J=8.4, 5.2 Hz, 1H), 1.03-0.91 (m, 4H); 13C-NMR (100 MHz, CDCl3) δ 151.9, 125.8, 79.1, 32.5, 6.9, 6.8.

1. temperatureto cool to room temperature
2. customquenched with a 10% aqueous solution of K2CO3
3. washThe organic layer was washed with 10% K2CO3
4. concentrationThe combined organic layers were concentrated

ORD-Eintrag

ord-f3c334e7089048ccbd0929c148623828

Quelldatensatz

uspto-grants-2010_12

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US07858804B2