[Br:1][CH:2]([CH2:6][CH2:7][CH2:8][CH2:9][CH3:10])[C:3]([OH:5])=[O:4].C(N(CC)CC)C.Cl[CH2:19][C:20](=[O:22])[CH3:21].Cl>CN(C)C=O>[Br:1][CH:2]([CH2:6][CH2:7][CH2:8][CH2:9][CH3:10])[C:3]([O:5][CH2:19][C:20](=[O:22])[CH3:21])=[O:4]2-Bromoheptanoic acid (86.0 g, 411.3 mmol) is placed in 600 ml of dimethylformamide, 49.95 g (493.6 mmol) of triethylamine are added dropwise thereto within 5 minutes at 20° C. and the pale yellow solution is stirred at room temperature for 15 minutes. Chloroacetone (57.07 g, 617 mmol) is added dropwise during 30 minutes and the yellow-brown suspension is stirred at room temperature for 90 minutes. The reaction mixture is poured on to 1 l of 1N HCl and ice and extracted in a separating funnel with 3×500 ml of ether. The organic phases are washed with 2×200 ml of water, dried over MgSO4 and concentrated on a rotary evaporator. Distillation at 86°-88° C./0.05 mbar yields 80.56 g (73.9%) of acetylmethyl 2-bromoheptanoate.
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