Propargyl bromide → Diethyl 2-methyl-2-propargyl-malonate

반응식

[CH3:1][CH:2]([C:8]([O:10][CH2:11][CH3:12])=[O:9])[C:3]([O:5][CH2:6][CH3:7])=[O:4].[CH2:13](Br)[C:14]#[CH:15].[Br-].[Na+]>>[CH3:1][C:2]([CH2:15][C:14]#[CH:13])([C:3]([O:5][CH2:6][CH3:7])=[O:4])[C:8]([O:10][CH2:11][CH3:12])=[O:9]

참가 물질

반응물 3

HCID 7842Propargyl bromide

HCID 11857Diethyl methylmalonate

HCID 253881Sodium Bromide

생성물 1

HCID 13924392Diethyl 2-methyl-2-propargyl-malonate

실험 절차

At 35° to 40° to C., with stirring, 174 g (1.0 ml) of diethyl methylmalonate are added dropwise to an alkoxide solution (prepared from 23 g of sodium and 800 ml of absolute ethanol), the mixture is stirred for a further hour and then at 45° C. 130.8 g (1.1 mol) of propargyl bromide are added dropwise. The mixture is refluxed for a further 2 hours. After cooling the precipitated sodium bromide is separated by suction filtering and the filtrate is substantially evaporated in vacuo. The residue is stirred into ice water and the aqueous solution is extracted several times with ether. The combined organic phases are dried and evaporated to dryness in vacuo. The resulting oil is used in the next stage without any further purification.