181955-79-3, 181955-79-3 1,4-Di-Boc-piperazine-2-carboxylic acid 11255979, apiperazines compound, is more and more widely used in various fields.
181955-79-3, 1,4-Di-Boc-piperazine-2-carboxylic acid is a piperazines compound, ?involved in a variety of chemical synthesis. Rlated chemical reaction is continuously updated
l54-Di(tert-butoxycarbonyl)piperazine-2-carboxylic acid (14.45 g, 43.7 mmol) was dissolved in THF (200 mL), and borane-THF complex (1.0 M solution in THF, 100 mL, 100 mmol) was added slowly. Upon complete addition, the reaction mixture was heated to 50 0C. After 2 h, the reaction mixture was allowed to cool to rt and was slowly quenched by the dropwise addition of MeOH (50 mL). After gas evolution ceased, the reaction mixture was heated to 50 0C for 1 h. Upon cooling to rt, the reaction mixture was concentrated under reduced pressure. The material was dissolved in THF (200 mL) and NaH (60% dispersion in mineral oil, 1.75 g, 43.7 mmol) was added portion wise. The reaction mixture was heated to 50 0C overnight. Upon cooling to rt, the reaction mixture was quenched with H2O (300 mL) and extracted with EtOAc (3 x 400 mL). The combined organics were dried over Na2SO4, filtered, and concentrated under reduced pressure. The material was purified by column chromatography (10 to 40% EtOAc in Hexanes gradient) to give 6.31 g (59%) of the desired product as a white solid. Rf = 0.43 in 80% EtOAc in Hexanes. 1.10 g (8%) of di-tert-butyl 2- (hydroxymethyl)piperazine-l,4-dicarboxylate was also isolated. Rf= 0.63 in 80% EtOAc in Hexanes.; Borane-THF complex (1.0 M solution in THF, 200 mL, 200 mmol) was added slowly to a solution of l,4-bis(tert-butoxycarbonyl)piperazine-2-carboxylic acid (30.3 g, 91.7 mmol) in THF (100 mL). Upon complete addition, the reaction mixture was heated to 50 0C for 2 h. Upon cooling to rt, the reaction mixture was carefully quenched by the dropwise addition of MeOH. After gas evolution ceased, the reaction mixture was concentrated under reduced pressure. The material was dissolved in EtOAc (300 mL) and washed with 1 N NaOH (2 x 200 mL) and brine (200 mL). The organics were dried over Na2SO4, filtered, and concentrated under reduced pressure. The material was twice dissolved in THF (50 mL) and concentrated under reduced pressure. The material was dissolved in THF (200 mL) and NaH (60% dispersion in mineral oil, 0.366 g, 0.916 mmol) was added portionwise. The reaction mixture was heated to reflux. After 1 h, the reaction mixture was allowed to cool to rt and was concentrated under reduced pressure. The material was dissolved in EtOAc (300 mL), washed with water (2 x 200 mL) and brine (200 mL), dried over Na2SO4, filtered, and concentrated under reduced pressure. The resulting solid was dissolved in EtOAc (200 mL) with heating, diluted with hexanes (200 mL) and allowed to cool to rt. The white, crystalline solid was collected by filtration after 5 h, washed with hexanes (2 x), and dried under vacuum. This gave 13.29 g (60%) of the product. The filtrate was concentrated under reduced pressure, dissolved in EtOAc (50 mL) with heating, and diluted with hexanes (200 mL). This was allowed to cool to rt and sit over the weekend. The white, crystalline solid was collected by filtration, washed with hexanes (2 x), and dried under vacuum. This gave an additional 4.49 g (20%) of the product. Analytical data: Rf = 0.43 in 80% EtOAc / Hexanes; 1H NMR (400 MHz, CDC13) delta 4.41 (t, J = 8.4 Hz, IH), 4.35-3.98 (br, 2H), 3.92 (dd, J = 5.6 and 8.8 Hz, IH), 3.80-3.72 (m, 2H), 2.98 (dt, J = 3.6 and 12.4 Hz, IH), 2.86-2.70 (br, IH), 2.70-2.55, (br, IH), 1.45 (s, 9H); 13C NMR (100 MHz, CDC13) delta 156.7, 154.2, 81.1, 65.5, 52.9, 47.7 (br), 43.4 (br), 41.1, 28.7. LC-MS: RT = 6.46 min; [M+Na]+ = 264.9. Anal. Calcd for CnH18N2O4: C3 54.53; H, 7.49; N, 11.56. Found: C, 54.38; H, 7.44; N, 1 1.35.
181955-79-3, 181955-79-3 1,4-Di-Boc-piperazine-2-carboxylic acid 11255979, apiperazines compound, is more and more widely used in various fields.
Reference:
Patent; CRITICAL THERAPEUTICS, INC.; WO2007/146066; (2007); A2;,
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