N,N-Dimethylaniline → 8,5-Dichloro-5H-dibenzo[b,e][1,4]diazepine

Participants

Reaction Conditions

Reaction Steps

N,N-dimethylaniline (5.1 ml, 40 mmol) and phosphorus oxychloride (2.8 ml, 30 mmol) was added to a mixture of 8-chloro-5,10-dihydro-dibenzo[b,e][1,4]diazepine-11-one (2.45 g, 10 mmol) in dry toluene (20 ml). The mixture was shaken at 95° C. for 2 h. The temperature was then decreased and the excess N,N-dimethylaniline and phosphorus oxychloride were removed at reduced pressure using an oil pump. The remaining oil was dissolved in dioxane (20 ml) and aqueous Na2CO3-solution (10 ml, 2 M) was added. The two-phase mixture was shaken at 80° C. for 30 min. The temperature was then decreased and ether was added to the reaction mixture. The ethereal phase was washed with saturated aqueous NaCl-solution, dried (Na2SO4) and finally concentrated at reduced pressure. The obtained oil crystallized upon standing at room temperature. Recrystallization (heptane-ether) gave 1.8 g (69%) of the title compound (160FE64). 1H NMR (CDCl3) δ 7.61 (dd, 1 H, J=1.4, 7.8 Hz), 7.31 (dt, 1 H, J=1.5, 8.0 Hz), 7.15 (d, 1 H, J=2.5 Hz), 7.02 (m 2 H), 6.66 (dd, 1 H, J=1.0, 7.8 Hz), 6.58 (d, 1 H, J=8.4 Hz), 4.94 (bs, 1H). 13C NMR (CDCl3) δ 157.2, 152.4, 140.3, 138.9, 134.0, 131.9, 129.7, 128.5, 128.0, 127.0, 123.5, 121.0, 119.8.

Provenance & Evidence