[OH:1][C:2]1[CH:12]=[CH:11][C:5]([C:6]([O:8][CH2:9][CH3:10])=[O:7])=[CH:4][CH:3]=1.Cl.Cl[CH2:15][CH2:16][N:17]1[CH2:22][CH2:21][CH2:20][CH2:19][CH2:18]1.C(=O)([O-])[O-].[K+].[K+].C(C(C)=O)C>O.C(OCC)(=O)C.C(#N)C.C(N(CC)CC)C>[N:17]1([CH2:16][CH2:15][O:1][C:2]2[CH:3]=[CH:4][C:5]([C:6]([O:8][CH2:9][CH3:10])=[O:7])=[CH:11][CH:12]=2)[CH2:22][CH2:21][CH2:20][CH2:19][CH2:18]1A mixture of ethyl 4-hydroxybenzoate (8.31 g), 1-(2-chloroethyl)piperidine monohydrochloride (10.13 g), potassium carbonate (16.59 g), and methyl ethyl ketone (60 mL) was heated to 80° C. After one hour, the mixture was cooled to about 55° C. and treated with additional 1-(2-chloroethyl)piperidine mono-hydrochloride (0.92 g). The resulting mixture was heated to 80° C. The reaction was monitored by thin layer chromatography (TLC), using silica-gel plates and ethyl acetate/acetonitrile/triethylamine (10:6:1, v/v). Additional portions of 1-(2-chloroethyl)piperidine hydrochloride are added until the starting 4-hydroxybenzoate ester is consumed. Upon complete reaction, the reaction mixture was treated with water (60 mL) and allowed to cool to room temperature. The aqueous layer was discarded and the organic layer concentrated in vacuo at 40° C. and 40 mm Hg. The resulting oil was used in the next step without further purification.
Loading…
