393781-71-0, 1-Boc-2-Ethylpiperazine is a piperazines compound, ?involved in a variety of chemical synthesis. Rlated chemical reaction is continuously updated
To a solution of 1 ,1-dimethylethyl 2-ethyl-1-piperazinecarboxylate (100mg, 0.467 mmol) in DCM (5ml_) was added di-isopropylethylamine (0.253mL, 1.447 mmol), followed by gradual addition of 4-cyanobenzenesulfonyl chloride (103mg, 0.513 mmol). The reaction mixture was allowed to stir for 1 hour. The reaction mixture was diluted with DCM (1 OmL) and the solution was washed with saturated aqueous sodium bicarbonate solution (1OmL, twice), then with distilled water (1OmL). The organic layer was dried (MgSO4), filtered and reduced in vacuo to yield 1 ,1-dimethylethyl 4-[(4-cyanophenyl)sulfonyl]-2-ethyl-1-piperazinecarboxylate as a crude transparent oil (173mg), MS ES+ve m/z 280 (M+H-100). To 1 ,1-dimethylethyl 4-[(4-cyanophenyl)sulfonyl]-2-ethyl-1-piperazinecarboxylate (173mg, 0.456 mmol) was added hydrogen chloride 1 M solution in 1 ,4 dioxane (1OmL) solution, followed by the addition of 3 drops of water. The reaction mixture was allowed to stir for 14hours. After this time, 5M aqueous HCI (1 ml) was added and the mixture was stirred for 12hours. The reaction mixture was concentrated in vacuo to yield colourless oil. The colourless oil was dissolved in methanol (1 OmL) and passed down a SCX-2 column washing with two column volumes of methanol and eluting the product with 2N ammonia solution in methanol (three column volumes). The fraction containing eluted product was reduced in vacuo to yield 4-[(3-ethyl-1- piperazinyl)sulfonyl]benzonitrile (99mg) as a transparent oil, MS ES+ve m/z 280 (M+H).To a solution of 4-[(3-ethyl-1-piperazinyl)sulfonyl]benzonitrile (99mg, 0.354mol) in tetrahydrofuran (1OmL) was added triethylamine (0.074mL, 0.532mmol) followed by drop wise addition of benzoyl chloride (0.045mL, 0.390mmol). The reaction mixture was allowed to stir for 30minut.es. The reaction mixture was diluted with DCM (1 OmL) and the solution was washed with saturated aqueous sodium bicarbonate solution (1OmL, twice), then 0.1 M hydrochloric acid (1OmL). The organic layer was dried with (MgSO4), filtered and concentrated in vacuo to yield 144mg colourless oil. The oil was dissolved in minimum volume of hot ethyl acetate (~2ml), hot iso-hexane (10ml) was then added and allowed to cool to room temperature. The supernatant was decanted off, and residual solid triturated with diethyl ether (50ml), to yield a white solid (67mg, 37%).1H-NMR (CDCI3) delta 0.65-1.19 (3H, br m), 1.78-1.98 (2H, m), 2.20-2.40 (1 H, m), 2.40- 2.57 (1 H, m), 2.96-3.48 (1 H, m), 3.48-3.96 (3H, m), 4.21-5.01 (1 H, m), 7.28-7.31 (2H, m), 7.36-7.45 (3H, m), 7.81-7.89 (4H, m).MS ES+ve m/z 384 (M+H).The single enantiomers were isolated from the racemic 4-{[3-ethyl-4-(phenylcarbonyl)-1-piperazinyl]sulfonyl}benzonitrile (53mg) via chiral preparative chromatography using the following conditions:- Column: Chiralpak IC (20mm x 250mm, 5mum)- Eluent: Heptane: Ethanol 50:50 v/v pump-mixed – Flow rate =17. Omls/min- U.V. Absorbance (S) 215nm- Autosampler injection (250mul of sample in 20%Heptane/30%EtOH/50%DMF on column)- lsocratic Run time = 30 minutesIsolated enantiomers were analysed via chiral analytical chromatography using the following conditions:- Chiralpak IC (4.6mm x 250mm, 5mum)- Heptane: Ethanol 50:50 v/v pump-mixed – Flow rate =1. Omls/min- U.V. Absorbance (at) 215nm- Autosampler injection (1 Omul of sample in mobile phase on column)- lsocratic Run time = 30 minutesIsolated compounds: Example 5a: Faster running enantiomer (4-{[(3S)-3-ethyl-4-(phenylcarbonyl)-1- piperazinyl]sulfonyl}benzonitrile or 4-{[(3R)-3-ethyl-4-(phenylcarbonyl)-1- piperazinyl]sulfonyl}benzonitrile, 16mg)Retention time 19.37min, 393781-71-0
393781-71-0 1-Boc-2-Ethylpiperazine 18004789, apiperazines compound, is more and more widely used in various fields.
Reference£º
Patent; GLAXO GROUP LIMITED; BESWICK, Paul, John; CAMPBELL, Alister; CRIDLAND, Andrew; GLEAVE, Robert, James; PAGE, Lee, William; WO2010/102663; (2010); A1;,
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