Water → Methyl 2-(cis-3-hydroxycyclohexyloxymethyl)-6-methylbenzoate

Beteiligte Stoffe

Reaktionsschritte

5 g (42.8 mmol) of cis-1,3-cyclohexanediol were dissolved in 40 ml of chlorobenzene and 10 ml of 1,3-dimethyl-3,4,5,6-tetrahydro-2(1H)-pyrimidinone (DMPU, dimethylpropyleneurea), admixed at 20–23° C. with 3.36 g (30 mmol) of potassium tert-butoxide (KOtBu) and stirred. After 10–15 minutes, the mixture was cooled to 15–20° C. and 3.7 g (approx. 50%) of methyl 2-bromomethyl-6-methylbenzoate were added dropwise. The mixture was stirred at 20° C. for 1.5 h and then added to water. The organic phase was removed and concentrated under reduced pressure. The residue was taken up in NMP/water and, to remove impurities, washed twice with n-heptane. Subsequently, the product was isolated by extracting twice with MTBE. The combined MTBE phases were washed with water, dried (Na2SO4) and concentrated under reduced pressure. The residue (1.2 g) was chromatographed on silica gel (1:1 ethyl acetate/n-heptane). 580 mg of the desired compound were obtained as a slightly yellow oil; 1H-NMR (CDCl3), δ =1.27 (m, 1H), 1.45 (m, 1H), 1.55 (m, 1H), 1.74 (m, 1H), 1.83 (m, 1H), 2.05 (m, 1H), 2.34 (s, 3H), 3.47 (m, 1H), 3.72 (m, 1H), 3.91 (s, 3H), 4.58 (dd, 2H), 7.15 (d, 1H), 7.20 (d, 2H), 7.27 (m, 1H).

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