Ethyl Acetate → HCID 70981527, compound

Participants

Reaction Conditions

Reaction Steps

To a solution of 2-bromo-5-methyl-5,6-dihydrobenzo[d]thiazol-7(4H)-one (17.5 g, 71.24 mmol) in acetic acid (142 mL) at 80° C. was added dropwise bromine (3.30 mL, 64.12 mmol) over 30 minutes. Reaction mixture was stirred for 1 h at 80° C., cooled to room temperature and resulting solid collected by filtration. The filter cake was partitioned between dichloromethane/saturated sodium bicarbonate solution. The organic layer was washed with saturated sodium bicarbonate solution, brine, dried (MgSO4), filtered and concentrated. The residue was dissolved in dichloromethane (250 mL) and added dropwise over 2.5 h to a solution of 1,8-Diazabicyclo[5.4.0]undec-7-ene (19.5 mL, 130 mmol) in dichloromethane (1.5 L) at 0° C. Reaction mixture was stirred for 30 minutes, quenched with 1N HCl and stirred for 5 minutes. The organic layer was washed with brine, dried (MgSO4), filtered and concentrated. Purification by CombiFlash (220 g, 5 to 40% EtOAc/Hex) gave impure product. Recystallization from hot EtOAc/Hex gave pure product. NMR (400 MHz, CDCl3): δ 7.42 (s, 1H), 6.65 (s, 1H), 2.44 (s, 3H).

Provenance & Evidence