Sodium Hydroxide → 1-N-(propan-2-yl)benzene-1,2-diamine

Temperature

0 °C

To a mixture of ethanol (600 mL) and 2 M sodium hydroxide solution (320 mL) cooled in an ice bath was added Zn dust (59.5 g) slowly. While stirring the Zn slurry, N-isopropyl-N-(2-nitrophenyl)amine (41 g, 0.228 mol) dissolved in ethanol (50 mL) was added. The mixture was stirred at 0° C. for 30 min, then heated to 85° C. The mixture was stirred at 85° C. for about 12 h until the refluxing solution of the mixture became a colorless solution. The mixture was then cooled to 0° C. and filtered. The collected solid was rinsed with ethyl acetate (200 mL). The filtrate and rinsed solution were combined, and evaporated in vacuo to remove excess volatile solvents. During the concentration, the mixture became pale brown/yellow. The aqueous concentrate was extracted with ethyl acetate (800 mL). The organic solution was concentrated to dryness, to provide the title intermediate (33 g) as a brown-pink oil which was used in the next step without further treatment. 1H-NMR (CDCl3, 300 MHz): δ (ppm) 6.73-6.5 (m, 4H), 3.58-3.55 (hept, 1H), 1.2 (d, 6H).

1. temperaturecooled in an ice bath
2. additionwas added
3. temperatureheated to 85° C
4. stirringThe mixture was stirred at 85° C. for about 12 h until the refluxing solution of the mixture
5. temperatureThe mixture was then cooled to 0° C.
6. filtrationfiltered
7. washThe collected solid was rinsed with ethyl acetate (200 mL)
8. washThe filtrate and rinsed solution
9. customevaporated in vacuo
10. customto remove excess volatile solvents
11. concentrationDuring the concentration
12. concentrationThe aqueous concentrate
13. extractionwas extracted with ethyl acetate (800 mL)
14. concentrationThe organic solution was concentrated to dryness

ORD record

ord-fd82c32765a34808aa5443133d05d8f6

Source dataset

uspto-grants-2008_01

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07317022B2