Ammonia → 2,6-Dimethylaniline

A solution of 19.7 g (0.158 mole) of 2,6-dimethyl-cyclohex-2-en-1-one in 180 ml of conc. ammonia is heated, after the addition of 4.0 g of palladium on charcoal (5%), in a hydrogenating autoclave for 4 hours at 280°-290° C., whereby a pressure of 20 bars is established, and is then maintained under these conditions for 5 hours. Cooling and pressure release are then carried out; the contents are again heated for about 5 hours and the pressure is again released. In order to effect the complete removal of hydrogen, the procedure of heating and pressure release is carried out in all three times. An addition is then made of 150 ml of ether and the catalyst is filtered off. The filter residue is washed three times alternately with 100 ml of ether and water, respectively. The mother liquor is extracted, after separation of the ether phase, five times with 150 ml of ether each time. The combined ether phases are dried over magnesium sulphate. After the ether has been distilled off, there remains 17.0 g of crude 2,6-dimethylaniline, from which is obtained, by distillation in a water-jet vacuum, 12.0 g (63% of theory) of pure 2,6-dimethylaniline; b.p. 103° C./ 18 Torr.

1. temperatureis then maintained under these conditions for 5 hours
2. temperatureCooling
3. temperaturethe contents are again heated for about 5 hours
4. customthe complete removal of hydrogen
5. temperaturethe procedure of heating
6. additionAn addition
7. filtrationthe catalyst is filtered off
8. washThe filter residue is washed three times alternately with 100 ml of ether and water
9. extractionThe mother liquor is extracted
10. customafter separation of the ether phase, five times with 150 ml of ether each time
11. dry with materialThe combined ether phases are dried over magnesium sulphate
12. distillationAfter the ether has been distilled off

ORD record

ord-036932c24ecb4eefa4052893f006e12e

Source dataset

uspto-grants-1980_02

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US04188341