bis[(2-methylpropan-2-yl)oxy] carbonate

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: In N,N-dimethylformamide (20 ml), 1-tert-butoxycarbonyl-2-carboxymethyl-4-[(6-chloronaphthalen-2-yl)sulfonyl]piperazine (800 mg) was dissolved, followed by the addition of pyridine (0.85 ml), ammonium bicarbonate (417 mg) and di-tert-butoxy carbonate (1.15 g). The resulting mixture was stirred at room temperature for 7 hours. After concentration of the reaction mixture under reduced pressure, the residue was added with dichloromethane, washed with 1N hydrochloric acid and a saturated aqueous solution of sodium bicarbonate, each once and then dried over anhydrous sodium sulfate. The solvent was then distilled off under reduced pressure. After the addition of saturated aqueous hydrochloric acid in ethanol (30 ml) to the residue, the resulting mixture was concentrated under reduced pressure. While washing with ethanol, the solid thus precipitated was removed by filtration. The filtrate was then concentrated under reduced pressure. The residue was crystallized in methanol, whereby the title compound (426 mg) was obtained as a colorless solid. washed with 1N hydrochloric acid a saturated aqueous solution of sodium bicarbonate, each once and then dried over anhydrous sodium sulfate The solvent was then distilled off under reduced pressure After the addition of saturated aqueous hydrochloric acid in ethanol (30 ml) to the residue the resulting mixture was concentrated under reduced pressure While washing with ethanol the solid thus precipitated was removed by filtration The filtrate was then concentrated under reduced pressure The residue was crystallized in methanol

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: In N,N-dimethylformamide (20 ml), 1-tert-butoxycarbonyl-2-carboxymethyl-4-[(6-chloronaphthalen-2-yl)sulfonyl]piperazine (800 mg) was dissolved, followed by the addition of pyridine (0.85 ml), ammonium bicarbonate (417 mg) and di-tert-butoxy carbonate (1.15 g). The resulting mixture was stirred at room temperature for 7 hours. After concentration of the reaction mixture under reduced pressure, the residue was added with dichloromethane, washed with 1N hydrochloric acid and a saturated aqueous solution of sodium bicarbonate, each once and then dried over anhydrous sodium sulfate. The solvent was then distilled off under reduced pressure. After the addition of saturated aqueous hydrochloric acid in ethanol (30 ml) to the residue, the resulting mixture was concentrated under reduced pressure. While washing with ethanol, the solid thus precipitated was removed by filtration. The filtrate was then concentrated under reduced pressure. The residue was crystallized in methanol, whereby the title compound (426 mg) was obtained as a colorless solid. washed with 1N hydrochloric acid a saturated aqueous solution of sodium bicarbonate, each once and then dried over anhydrous sodium sulfate The solvent was then distilled off under reduced pressure After the addition of saturated aqueous hydrochloric acid in ethanol (30 ml) to the residue the resulting mixture was concentrated under reduced pressure While washing with ethanol the solid thus precipitated was removed by filtration The filtrate was then concentrated under reduced pressure The residue was crystallized in methanol

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: In N,N-dimethylformamide (20 ml), 1-tert-butoxycarbonyl-2-carboxymethyl-4-[(6-chloronaphthalen-2-yl)sulfonyl]piperazine (800 mg) was dissolved, followed by the addition of pyridine (0.85 ml), ammonium bicarbonate (417 mg) and di-tert-butoxy carbonate (1.15 g). The resulting mixture was stirred at room temperature for 7 hours. After concentration of the reaction mixture under reduced pressure, the residue was added with dichloromethane, washed with 1N hydrochloric acid and a saturated aqueous solution of sodium bicarbonate, each once and then dried over anhydrous sodium sulfate. The solvent was then distilled off under reduced pressure. After the addition of saturated aqueous hydrochloric acid in ethanol (30 ml) to the residue, the resulting mixture was concentrated under reduced pressure. While washing with ethanol, the solid thus precipitated was removed by filtration. The filtrate was then concentrated under reduced pressure. The residue was crystallized in methanol, whereby the title compound (426 mg) was obtained as a colorless solid. washed with 1N hydrochloric acid a saturated aqueous solution of sodium bicarbonate, each once and then dried over anhydrous sodium sulfate The solvent was then distilled off under reduced pressure After the addition of saturated aqueous hydrochloric acid in ethanol (30 ml) to the residue the resulting mixture was concentrated under reduced pressure While washing with ethanol the solid thus precipitated was removed by filtration The filtrate was then concentrated under reduced pressure The residue was crystallized in methanol

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: In N,N-dimethylformamide (20 ml), 1-tert-butoxycarbonyl-2-carboxymethyl-4-[(6-chloronaphthalen-2-yl)sulfonyl]piperazine (800 mg) was dissolved, followed by the addition of pyridine (0.85 ml), ammonium bicarbonate (417 mg) and di-tert-butoxy carbonate (1.15 g). The resulting mixture was stirred at room temperature for 7 hours. After concentration of the reaction mixture under reduced pressure, the residue was added with dichloromethane, washed with 1N hydrochloric acid and a saturated aqueous solution of sodium bicarbonate, each once and then dried over anhydrous sodium sulfate. The solvent was then distilled off under reduced pressure. After the addition of saturated aqueous hydrochloric acid in ethanol (30 ml) to the residue, the resulting mixture was concentrated under reduced pressure. While washing with ethanol, the solid thus precipitated was removed by filtration. The filtrate was then concentrated under reduced pressure. The residue was crystallized in methanol, whereby the title compound (426 mg) was obtained as a colorless solid. washed with 1N hydrochloric acid a saturated aqueous solution of sodium bicarbonate, each once and then dried over anhydrous sodium sulfate The solvent was then distilled off under reduced pressure After the addition of saturated aqueous hydrochloric acid in ethanol (30 ml) to the residue the resulting mixture was concentrated under reduced pressure While washing with ethanol the solid thus precipitated was removed by filtration The filtrate was then concentrated under reduced pressure The residue was crystallized in methanol