C1(CO[C:9]2[CH:10]=[CH:11][C:12](C(=O)CCl)=[C:13]3[C:18]=2[NH:17][C:16](=[O:19])[CH:15]=[CH:14]3)C=CC=CC=1.CB1N2CCC[C@@H]2C(C2C=CC=CC=2)(C2C=CC=CC=2)O1>C1(C)C=CC=CC=1.C1COCC1>[NH:17]1[C:18]2[C:13](=[CH:12][CH:11]=[CH:10][CH:9]=2)[CH:14]=[CH:15][C:16]1=[O:19]A dry 3 L, 4-necked flask equipped with a mechanical stirrer, thermometer, addition funnel and refluxing condenser is charged with 50 g 8-(phenylmethoxy)-5-(α-chloroacetyl)-(1H)-quinolin-2-one and 600 mL dry THF under N2. Then 15 mL of a 1 molar solution of (R)-tetrahydro-1-methyl-3,3-diphenyl-(1H,3H)-pyrrolo[1,2-c][1,3,2]-oxazaborole in toluene was added. The mixture was cooled to an internal temperature of 0-2° C. and while maintaining an internal temperature of 0-2° C., 153 mL of a 1 molar solution of BH3 in THF was added over 1-2 hours. The reaction was stirred for another hour at an internal temperature of 0-2° C. and then quenched by addition of 65 mL methanol. The resulting solution was warmed to 25° C. and concentrated to a volume of 250 mL (50° C./200 mbar). To this concentrate was added a mixture of 713 mL water and 37 g HCl 37%. During the addition 8-(phenylmethoxy)-5-((R)-2-chloro-1-hydroxy-ethyl)-(1H)-quinolin-2-one precipitated as a nearly colourless precipitation. The resulting suspension was stirred for 30 minutes at 25° C., filtrated and washed with 220 mL water in several portions. Drying in a vacuum drier at 50° C. for 12 hours resulted in 47.41 g of 8-(phenylmethoxy)-5-((R)-2-chloro-1-hydroxy-ethyl)-(1H-quinolin-2-one as a slightly yellowish powder.
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