3-Chlorobenzoic Acid → Loratadine N-oxide

Reaction equation

[Cl:1][C:2]1[CH:3]=[CH:4][C:5]2[C:15](=[C:16]3[CH2:21][CH2:20][N:19]([C:22]([O:24][CH2:25][CH3:26])=[O:23])[CH2:18][CH2:17]3)[C:10]3=[N:11][CH:12]=[CH:13][CH:14]=[C:9]3[CH2:8][CH2:7][C:6]=2[CH:27]=1.ClC1C=C(C=CC=1)C(O)=[O:33]>ClCl.C(Cl)Cl>[Cl:1][C:2]1[CH:3]=[CH:4][C:5]2[C:15](=[C:16]3[CH2:17][CH2:18][N:19]([C:22]([O:24][CH2:25][CH3:26])=[O:23])[CH2:20][CH2:21]3)[C:10]3=[N+:11]([O-:33])[CH:12]=[CH:13][CH:14]=[C:9]3[CH2:8][CH2:7][C:6]=2[CH:27]=1

Participants

Procedure

8-chloro-11-(1-ethoxycarbonyl-4-piperidylidene)-6,11-dihydro-5H-benzo[5,6]cyclohepta[1,2-b]pyridine (5 g, 13.06 mmol) was dissolved in CH2 Cl2 at -10° C. 3-Chlorobenzoic acid (4.9 g, 15.67 mmol) was then added and the reaction mixture stirred for 95 minutes. The reaction mixture was taken up in CH2Cl2 and extracted with sodium bisulfite, 10% NaOH. The crude reaction product was purified on silica gel eluting first with 1% and then with 2% MeOH in CH2Cl2 to give the title compound (2.7 g, MH+ 399).