Dicyclohexylcarbodiimide → HCID 21030583, compound

Participants

Reaction Conditions

Reaction Steps

4-dimethyl-aminopyridine (122 mg, 1.0 mmol) and 2-(3,3-dimethylcyclohexyl)-2-propanol (2.6 g, 15 mmol), [which is obtainable from methylmagnesium chloride and 1-(3,3-dimethylcyclohexyl)-ethanone by a Grignard reaction] are added successively to a solution of 81% (propionyloxy) acetic acid (2.7 g, 16.5 mmol) in CH2Cl2 (15 ml). The reaction solution is now cooled to 0° C. and dicyclohexylcarbodiimide (3.4 g, 16.5 mmol), dissolved in CH2Cl2 (5 ml) is added. After 1 h at 0° C., the cooling is removed, and the reaction mixture is stirred for a further 16 h at room temperature. The precipitate that has precipitated is, then, filtered off, and the filtrate is freed from solvent in a rotary evaporator. The resulting crude product is taken up in n-pentane (20 ml) and the precipitate that forms is again filtered off. The filtrate is also washed twice with 0.5 M HCl and twice with saturated NaHCO3 solution, and the organic phase is then dried over Na2SO4, filtered off, and concentrated in a rotary evaporator. After purification by flash chromatography (cyclohexane/EtOAc=10:1, Rf=0.23) and subsequent bulb tube distillation (BTD: 221° C., 1.3 mbar), 3.1 g (73%) 2-[1-(3,3-dimethylcyclohexyl)-1-methylethoxy]-2-oxoethyl propionate is obtained as a colorless liquid.

Provenance & Evidence