Fuming sulfuric acid → Sulfuric Acid
Reaktionsgleichung
[Cl:1][C:2]1[CH:11]=[C:10]2[C:5]([C:6](=[O:12])[CH2:7][CH2:8][NH:9]2)=[CH:4][CH:3]=1.ClC1C=C(C=CC=1)NCCC(O)=O.[OH:26][S:27]([OH:30])(=[O:29])=[O:28].O=S(=O)=O>>[S:27](=[O:28])(=[O:26])([OH:30])[OH:29].[Cl:1][C:2]1[CH:11]=[C:10]2[C:5]([C:6](=[O:12])[CH2:7][CH2:8][NH:9]2)=[CH:4][CH:3]=1Komponenten
5
Versuchsvorschrift
A process for the preparation of 7-chloro-1,2,3,4-tetrahydroquinolin-4-one which comprises cyclising 3-m-chloroanilinopropionic acid by means of an oleum, then desulphonating the intermediate aromatic sulphonic acids of the formula: ##STR3## (wherein n is 1 or 2) by means of dilute sulphuric acid, and then isolating the 7-chloro-1,2,3,4-tetrahydroquinolin-4-one obtained.