反应详情

To an ice-cooled and stirred solution of 4-(1-(2-fluoro-4-biphenylyl)ethyl)-2-methylamino-5-thiazolecarboxylic acid (5.00 g, 14.0 mmoles) and dimethylformamide (1.03 g, 14.1 mmoles) in methylene chloride (200 ml) was added dropwise oxalyl chloride (3.93 g, 31.0 mmoles) and the mixture was stirred for 40 minutes. On the other hand, hydroxylamine hydrochloride (3.91 g, 56.3 mmoles) in water (5 ml) and triethylamine (8.55 g, 84.5 mmoles) were dissolved in tetrahydrofuran (100 ml), and to the mixture was added dropwise the above-mentioned reacted solution of thiazolecarboxylic acid. After stirring for 30 minutes, the reaction mixture was acidified to pH 4 with 1M hydrochloric acid and extracted with methylene chloride. The organic layer was washed with water, dried and concentrated under reduced pressure, and the residue was purified by silica gel column chromatography to obtain the desired 4-(1-(2-fluoro-4-biphenylyl)ethyl)-2-methylamino-5-thiazolecarbohydroxamic acid (2.50 g, 6.73 mmoles, 48%) as a light brown amorphous product.

1. stirringAfter stirring for 30 minutes
2. extractionextracted with methylene chloride
3. washThe organic layer was washed with water
4. customdried
5. concentrationconcentrated under reduced pressure
6. customthe residue was purified by silica gel column chromatography