[CH2:1]([O:9][C:10]1[N:11]=[N:12][C:13](Cl)=[CH:14][CH:15]=1)[CH2:2][CH2:3][CH2:4][CH2:5][CH2:6][CH2:7][CH3:8].C([Li])CCC.[BH:22]([OH:24])[OH:23]>C1COCC1.CCCCCC.C(OCC)C.[Cl-].[Cl-].[Zn+2]>[CH2:1]([O:9][C:10]1[N:11]=[N:12][C:13]([B:22]([OH:24])[OH:23])=[CH:14][CH:15]=1)[CH2:2][CH2:3][CH2:4][CH2:5][CH2:6][CH2:7][CH3:8]17.1 g (70.6 mmol) of 3-octyloxy-6-chloropyridazine are dissolved in 100 ml of absolute THF and cooled to -78° C. under a protective gas. 47.1 ml (75.2 mmol) of 1.6 molar n-butyllithium solution in hexane are then added dropwise over the course of 30 minutes. The mixture is stirred at -78° C. for a further 30 minutes. 216 ml (215.7 mmol) of 1.0 molar ZnCl2 solution in diethyl ether are subsequently slowly added dropwise, during which the temperature must not exceed -60° C. When the addition is complete, the mixture is stirred for a further 30 minutes. The crude boronic acid is employed directly, without isolation from the solution, for the subsequent couplings.
Loading…
