propan-2-yl 2-aminoacetate

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

Procedure: Diphenylidene isopropyl glycinate (2.0 g, 7.0 mmol) and 31 (1.4 g, 7.0 mmole) were dissolved in THF (10 ml). The solution was cooled to −10° C. tert-BuOLi (0.56 g, 7.0 mmole) was charged into the solution in several portions. The reaction was warmed up to room temperature slowly and stirred overnight. After quenched by addition of aqueous NH4Cl, the solvents were removed by distillation under vacuum. The residue was subjected to silica chromatography column eluted by hexane and EtOAc yielding 32 (3.0 g, 89%) as an oil, which was directly used in the next step. was charged into the solution in several portions After quenched by addition of aqueous NH4Cl the solvents were removed by distillation under vacuum eluted by hexane and EtOAc yielding 32 (3.0 g, 89%) as an oil, which

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

Procedure: Diphenylidene isopropyl glycinate (2.0 g, 7.0 mmol) and 31 (1.4 g, 7.0 mmole) were dissolved in THF (10 ml). The solution was cooled to −10° C. tert-BuOLi (0.56 g, 7.0 mmole) was charged into the solution in several portions. The reaction was warmed up to room temperature slowly and stirred overnight. After quenched by addition of aqueous NH4Cl, the solvents were removed by distillation under vacuum. The residue was subjected to silica chromatography column eluted by hexane and EtOAc yielding 32 (3.0 g, 89%) as an oil, which was directly used in the next step. was charged into the solution in several portions After quenched by addition of aqueous NH4Cl the solvents were removed by distillation under vacuum eluted by hexane and EtOAc yielding 32 (3.0 g, 89%) as an oil, which

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

Procedure: Diphenylidene isopropyl glycinate (2.0 g, 7.0 mmol) and 31 (1.4 g, 7.0 mmole) were dissolved in THF (10 ml). The solution was cooled to −10° C. tert-BuOLi (0.56 g, 7.0 mmole) was charged into the solution in several portions. The reaction was warmed up to room temperature slowly and stirred overnight. After quenched by addition of aqueous NH4Cl, the solvents were removed by distillation under vacuum. The residue was subjected to silica chromatography column eluted by hexane and EtOAc yielding 32 (3.0 g, 89%) as an oil, which was directly used in the next step. was charged into the solution in several portions After quenched by addition of aqueous NH4Cl the solvents were removed by distillation under vacuum eluted by hexane and EtOAc yielding 32 (3.0 g, 89%) as an oil, which

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

Procedure: 0.35 mol diphosgene is added dropwise over 1 hour to a mixture of 0.28 mol of glycine isopropyl ester and 0.4 g activated charcoal in 400 mL dioxane under N2. The reaction mixture is then heated and stirred at reflux for 21/2 hours. The reaction mixture is then cooled, filtered, and concentrated to dryness by rotary evaporator, keeping exposure to moisture to a minimum. The crude product is redissolved in 100 mL THF, and the pH of the solution is adjusted to 5.5-6.0 by addition of pyridine. The product mixture is again filtered, and the product is purified by fractional distillation to give glycine isopropyl ester isocyanate. The reaction mixture is then heated at reflux for 21/2 hours The reaction mixture is then cooled filtered concentrated to dryness by rotary evaporator The crude product is redissolved in 100 mL THF the pH of the solution is adjusted to 5.5-6.0 by addition of pyridine The product mixture is again filtered the product is purified by fractional distillation