Dimethylformamide → 2-Acetoxymethyl-5-(benzothiazol-2-yl)-1-(tetrahydropyran-4-yl)benzimidazole

Temperature

50 °C

A 4-neck flask (500 mL) equipped with a reflux condenser was charged with 2-acetoxymethyl-1-(tetrahydropyran-4-yl)benzimidazole-5-carboxylic acid (5.98 g, 18.79 mmol), anhydrous tetrahydrofuran (158 mL), and oxalyl chloride (2.86 g, 22.50 mmol), and anhydrous N,N-dimethylformamide (1 mL) was then added dropwise at room temperature, after which the reaction mixture was stirred at 50° C. for 5 hours. After being allowed to cool to room temperature, the solvent was distilled off under reduced pressure to give a pale yellow residue, which was taken up in anhydrous tetrahydrofuran (100 mL), and then 2-aminobenzenethiol (2.35 g, 18.79 mmol) was added, and this was stirred for 19 hours at 50° C. This was allowed to cool to room temperature, and after the precipitated crystals were filtered off, they were successively washed with distilled water and dried under reduced pressure with heating to yield the title compound (9.00 g, quant.) as a white solid.

1. customA 4-neck flask (500 mL) equipped with a reflux condenser
2. additionwas then added dropwise at room temperature
3. temperatureto cool to room temperature
4. distillationthe solvent was distilled off under reduced pressure
5. customto give a pale yellow residue, which
6. stirringthis was stirred for 19 hours at 50° C
7. temperatureto cool to room temperature
8. filtrationafter the precipitated crystals were filtered off
9. washthey were successively washed with distilled water
10. customdried under reduced pressure
11. temperaturewith heating

ORD record

ord-a55a02ffefe847a29485bba91e7d4d06

Source dataset

uspto-grants-2014_09

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08829035B2