(2R)-2-aminopropanamide

Conditions: temp:-10.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A solution of Cbz-Pro-OH (10.1 gm) in 2-propanol (IPA, 100 mL) was cooled to -5° C., and NMM (4.4 mL) was added with additional cooling to -10° C. iso-Butyl chloroformate (5.2 mL) was added dropwise while maintaining the temperature at -10° to -15° C. After the addition was complete, a solution of HCl.D-Ala-NH2 (5.0 gm) and NMM (4.4 mL) in water (50 mL) was added and the mixture was stirred at -10° C. for another 30 minutes. The cooling bath was then removed and the solution stirred another three hours. The reaction was quenched in a mixture of EtOAc (200 mL) and water (100 mL) containing NaHCO3 (5 gm) and NaCl (5 gm). The layers were separated and the aqueous layer extracted with EtOAc (2×100 mL). The organic layers were combined and washed with water (2×50 mL) and then concentrated in vacuo to dryness. The residue was taken up in EtOAc (250 mL) and the solution washed with water (2×50 mL) to remove any residual IPA. The organic solution was concentrated in vacuo to about 50 mL and treated with EtOAc (50 mL) and heptane (50 mL) and the product crystallized. The solids were filtered, washed on the filter with heptane and dried in vacuo to yield 8.2 gm Cbz-Pro-D-Ala-NH2. HPLC: 99.2 pa %, [α]D =-11.2 (CHCl3). was added dropwise while maintaining the temperature at -10° to -15° C After the addition The cooling bath was then removed the solution stirred another three hours The reaction was quenched in a mixture of EtOAc (200 mL) and water (100 mL) containing NaHCO3 (5 gm) and NaCl (5 gm) The layers were separated the aqueous layer extracted with EtOAc (2×100 mL) washed with water (2×50 mL) concentrated in vacuo to dryness the solution washed with water (2×50 mL) to remove any residual IPA The organic solution was concentrated in vacuo to about 50 mL treated with EtOAc (50 mL) and heptane (50 mL) the product crystallized The solids were filtered washed on the filter with heptane dried in vacuo

Conditions: temp:-10.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A solution of Cbz-Pro-OH (10.1 gm) in 2-propanol (IPA, 100 mL) was cooled to -5° C., and NMM (4.4 mL) was added with additional cooling to -10° C. iso-Butyl chloroformate (5.2 mL) was added dropwise while maintaining the temperature at -10° to -15° C. After the addition was complete, a solution of HCl.D-Ala-NH2 (5.0 gm) and NMM (4.4 mL) in water (50 mL) was added and the mixture was stirred at -10° C. for another 30 minutes. The cooling bath was then removed and the solution stirred another three hours. The reaction was quenched in a mixture of EtOAc (200 mL) and water (100 mL) containing NaHCO3 (5 gm) and NaCl (5 gm). The layers were separated and the aqueous layer extracted with EtOAc (2×100 mL). The organic layers were combined and washed with water (2×50 mL) and then concentrated in vacuo to dryness. The residue was taken up in EtOAc (250 mL) and the solution washed with water (2×50 mL) to remove any residual IPA. The organic solution was concentrated in vacuo to about 50 mL and treated with EtOAc (50 mL) and heptane (50 mL) and the product crystallized. The solids were filtered, washed on the filter with heptane and dried in vacuo to yield 8.2 gm Cbz-Pro-D-Ala-NH2. HPLC: 99.2 pa %, [a]D =-11.2 (CHCl3). was added dropwise while maintaining the temperature at -10° to -15° C After the addition The cooling bath was then removed the solution stirred another three hours The reaction was quenched in a mixture of EtOAc (200 mL) and water (100 mL) containing NaHCO3 (5 gm) and NaCl (5 gm) The layers were separated the aqueous layer extracted with EtOAc (2×100 mL) washed with water (2×50 mL) concentrated in vacuo to dryness the solution washed with water (2×50 mL) to remove any residual IPA The organic solution was concentrated in vacuo to about 50 mL treated with EtOAc (50 mL) and heptane (50 mL) the product crystallized The solids were filtered washed on the filter with heptane dried in vacuo

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

Procedure: The treatment of one solution at 6% of hydrochloride of α-aminopropionamide in water (pH included between 6.5 to 8.5) can be effected by a suspension of cells of strain A4 at 20 to 40 g of dry matter per liter. Quantitatively L-α-alanine (50%) and D-α-aminopropionamide (50%) is obtained. This amide D can either be hydrolized in D-α-alanine by action of strain R 312 (CBS 717.73) or racemized and recycled with a view to the preparation of L-α-alanine.

Conditions: temp:0.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: 3.36 g of DCC are added to a stirred solution of 5.4 g (16 mmol) of Fmoc-Pro-OH, 2 g of HCl.H-D-Ala-NH2 and 2.24 g of HOBt in 30 ml of dimethylformamide at 0° C. The mixture is left to stir at 0° C. for 1 hour and to stand at room temperature overnight. The precipitate is filtered off with suction and the filtrate is concentrated. The residue is dissolved in ethyl acetate and extracted by shaking successively with water, twice with saturated NaHCO3 solution, water, KHSO4 buffer and water. Fmoc-Pro-D-Ala-NH2 precipitates in the ethyl acetate phase during this and is filtered off with suction. The ethyl acetate mother liquor is concentrated and triturated with diethyl ether and filtered with suction. at 0° C The mixture is left to stand at room temperature overnight The precipitate is filtered off with suction the filtrate is concentrated The residue is dissolved in ethyl acetate extracted by shaking successively with water, twice with saturated NaHCO3 solution, water, KHSO4 buffer and water Fmoc-Pro-D-Ala-NH2 precipitates in the ethyl acetate phase during this and is filtered off with suction The ethyl acetate mother liquor is concentrated triturated with diethyl ether filtered with suction

Conditions: temp:-10.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A solution of Cbz-Pro-OH (10.1 gm) in 2-propanol (IPA, 100 mL) was cooled to -5° C., and NMM (4.4 mL) was added with additional cooling to -10° C. iso-Butyl chloroformate (5.2 mL) was added dropwise while maintaining the temperature at -10° to -15° C. After the addition was complete, a solution of HCl.D-Ala-NH2 (5.0 gm) and NMM (4.4 mL) in water (50 mL) was added and the mixture was stirred at -10° C. for another 30 minutes. The cooling bath was then removed and the solution stirred another three hours. The reaction was quenched in a mixture of EtOAc (200 mL) and water (100 mL) containing NaHCO3 (5 gm) and NaCl (5 gm). The layers were separated and the aqueous layer extracted with EtOAc (2×100 mL). The organic layers were combined and washed with water (2×50 mL) and then concentrated in vacuo to dryness. The residue was taken up in EtOAc (250 mL) and the solution washed with water (2×50 mL) to remove any residual IPA. The organic solution was concentrated in vacuo to about 50 mL and treated with EtOAc (50 mL) and heptane (50 mL) and the product crystallized. The solids were filtered, washed on the filter with heptane and dried in vacuo to yield 8.2 gm Cbz-Pro-D-Ala-NH2. HPLC: 99.2 pa %, [α]D =-11.2 (CHCl3). was added dropwise while maintaining the temperature at -10° to -15° C After the addition The cooling bath was then removed the solution stirred another three hours The reaction was quenched in a mixture of EtOAc (200 mL) and water (100 mL) containing NaHCO3 (5 gm) and NaCl (5 gm) The layers were separated the aqueous layer extracted with EtOAc (2×100 mL) washed with water (2×50 mL) concentrated in vacuo to dryness the solution washed with water (2×50 mL) to remove any residual IPA The organic solution was concentrated in vacuo to about 50 mL treated with EtOAc (50 mL) and heptane (50 mL) the product crystallized The solids were filtered washed on the filter with heptane dried in vacuo

Conditions: temp:-10.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A solution of Cbz-Pro-OH (10.1 gm) in 2-propanol (IPA, 100 mL) was cooled to -5° C., and NMM (4.4 mL) was added with additional cooling to -10° C. iso-Butyl chloroformate (5.2 mL) was added dropwise while maintaining the temperature at -10° to -15° C. After the addition was complete, a solution of HCl.D-Ala-NH2 (5.0 gm) and NMM (4.4 mL) in water (50 mL) was added and the mixture was stirred at -10° C. for another 30 minutes. The cooling bath was then removed and the solution stirred another three hours. The reaction was quenched in a mixture of EtOAc (200 mL) and water (100 mL) containing NaHCO3 (5 gm) and NaCl (5 gm). The layers were separated and the aqueous layer extracted with EtOAc (2×100 mL). The organic layers were combined and washed with water (2×50 mL) and then concentrated in vacuo to dryness. The residue was taken up in EtOAc (250 mL) and the solution washed with water (2×50 mL) to remove any residual IPA. The organic solution was concentrated in vacuo to about 50 mL and treated with EtOAc (50 mL) and heptane (50 mL) and the product crystallized. The solids were filtered, washed on the filter with heptane and dried in vacuo to yield 8.2 gm Cbz-Pro-D-Ala-NH2. HPLC: 99.2 pa %, [a]D =-11.2 (CHCl3). was added dropwise while maintaining the temperature at -10° to -15° C After the addition The cooling bath was then removed the solution stirred another three hours The reaction was quenched in a mixture of EtOAc (200 mL) and water (100 mL) containing NaHCO3 (5 gm) and NaCl (5 gm) The layers were separated the aqueous layer extracted with EtOAc (2×100 mL) washed with water (2×50 mL) concentrated in vacuo to dryness the solution washed with water (2×50 mL) to remove any residual IPA The organic solution was concentrated in vacuo to about 50 mL treated with EtOAc (50 mL) and heptane (50 mL) the product crystallized The solids were filtered washed on the filter with heptane dried in vacuo