N,N-Dimethylaniline → 11-Chlorodibenzo(b,f)(1,4)thiazepine
Reaction equation
[CH:1]1[C:6]2[C:7](=O)[NH:8][C:9]3[CH:15]=[CH:14][CH:13]=[CH:12][C:10]=3[S:11][C:5]=2[CH:4]=[CH:3][CH:2]=1.P(Cl)(Cl)([Cl:19])=O.CN(C)C1C=CC=CC=1.N(Cl)Cl>>[Cl:19][C:7]1[C:6]2[CH:1]=[CH:2][CH:3]=[CH:4][C:5]=2[S:11][C:10]2[CH:12]=[CH:13][CH:14]=[CH:15][C:9]=2[N:8]=1Participants
5
Procedure
A 2 liter round-bottom flask equipped with a magnetic stirring bar and reflux condenser with a nitrogen inlet was charged with 115.0 g (0.506 mole) of dibenzo[b,f][1,4]thiazepine-11(10-H)one, phosphorous oxychloride 700 ml (7.5 moles) and N,N-dimethylaniline 38.0 g (0.313 mole). The grey suspension was heated to gentle refluxing using a heating mantle. After 6 hours of heating, the resulting amber solution was allowed to cool to room temperature (from about 18°-25°C.) and was analyzed by thin-layer chromatography (TLC) using silica gel plates, developed with ether-hexane (1:1) and detected with ultraviolet light. Analysis revealed the desired imino chloride, Rf =0.70, and an absence of starting lactam.