Water → 2,4,6-Trichloroaniline

A 5-L, two-necked, round-bottomed flask equipped with magnetic stirbar was charged with 50 g freshly distilled aniline (0.54 mol) in 1 L MeCN. One neck was equipped with a reflux condenser and N2 purge, and the second neck was glass stoppered. The solution was brought to reflux. N-Chlorosuccimide (86 g, 1 equiv) was added through the glass-stoppered neck in one portion. The color of the reaction became purple-brown. After 1 h, a second addition of 86 g NCS (1 equiv) was made in one portion. After 1 h, NMR of the reaction mixture showed only traces of NCS remained in addition to formation of primarily 2,4-dichloroaniline. The final addition of 86 g NCS (1 equiv) was made in eight ˜10-g portions, reaction occurs with a vigorous exotherm. After the addition, TLC showed the reaction was complete. The mixture was cooled to room temperature and poured into 3 L vigorously stirred H2O. After stirring 1 h, the light purple solid was collected on a coarse-porosity glass frit, washed with 1 L H2O, and air-dried on the frit for 2 h. The crude was dissolved in 1 L Et2O and washed with 500 mL H2O and 500 mL brine. The organic layer was dried with anhydrous MgSO4 and filtered. The filtrate was treated with 11 g Darco G-60 for 1 h. The mixture was filtered through diatomaceous earth, and the solvent was rotary evaporated. The red-brown solid was dissolved in 1 L hexanes. The solution was filtered through 300 g SiO2 on a medium-porosity glass frit that removed most of the color. The filtrates were rotary evaporated, leaving 111.6 g of the title compound as a pale yellow solid that was >97% by 1 H NMR (88%). Recrystallization from EtOH gave the title compound in analytically pure form as soft, colorless needles. Mp 68-70° C., 77.5° C. δH (CDCl3): 7.13 (s, 2 H), 4.36 (bs, NH2); δC (CDCl3): 139.24, 127.81, 122.06, 119.92. Elemental analysis calculated for C6H4Cl3N: C, 36.68; H, 2.05; N, 7.13. Found: C, 36.87; H, 1.93; N, 7.07.

1. customOne neck was equipped with a reflux condenser
2. customN2 purge
3. temperatureto reflux
4. additionN-Chlorosuccimide (86 g, 1 equiv) was added through the glass-stoppered neck in one portion
5. waitAfter 1 h
6. customwas made in eight ˜10-g portions, reaction
7. additionAfter the addition, TLC
8. customthe light purple solid was collected on a coarse-porosity glass frit
9. washwashed with 1 L H2O
10. customair-dried on the frit for 2 h
11. dissolutionThe crude was dissolved in 1 L Et2O
12. washwashed with 500 mL H2O and 500 mL brine
13. dry with materialThe organic layer was dried with anhydrous MgSO4
14. filtrationfiltered
15. additionThe filtrate was treated with 11 g Darco
16. waitfor 1 h
17. filtrationThe mixture was filtered through diatomaceous earth
18. dissolutionThe red-brown solid was dissolved in 1 L hexanes
19. filtrationThe solution was filtered through 300 g SiO2 on a medium-porosity glass frit that
20. customremoved most of the color

ORD record

ord-91f16bb918e644a0afa4f01c1d5ce7a3

Source dataset

uspto-grants-2010_08

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07767857B1