N,N-Dimethylaniline → 3804-32-8

Temperature

0 °C

An ice-cold solution of sodium nitrite (1.65 g, 23.9 mmol) in water (15 mL) was added slowly (via syringe) to a stirring mixture at 0° C. of 2-aminobenzothiazole (3.78 g, 25.2 mmol) in water (50 mL) and concentrated sulfuric acid (7.0 mL, 126.7 mmol). During addition, the temperature was kept below 5° C. The resultant orange mixture was stirred at 0° C. for 15 minutes, then N,N-dimethylaniline was added dropwise causing the mixture to turn dark brown-black. The mixture was stirred at 0° C. for 15 minutes, an aqueous solution of sodium acetate (4.32 g in 20 mL of water) was added dropwise, stirred for 1 hour, basified with 25% sodium hydroxide solution to a pH ~12 and allowed to warm to room temperature. The mixture was filtered, the solid was washed with cold water, recrystallized from methanol, then chromatographed (silica gel, 2% methanol in methylene chloride) to give the title compound as a green solid, mp 243-246° C.

1. additionDuring addition
2. customwas kept below 5° C
3. stirringThe mixture was stirred at 0° C. for 15 minutes
4. stirringstirred for 1 hour
5. temperatureto warm to room temperature
6. filtrationThe mixture was filtered
7. washthe solid was washed with cold water
8. customrecrystallized from methanol
9. customchromatographed (silica gel, 2% methanol in methylene chloride)

ORD record

ord-00166c04a6524df2b4ae4627045d63bc

Source dataset

uspto-grants-1999_12

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US06001331