(2R)-2-acetamido-3-hydroxypropanoic acid

Conditions: temp:32.51; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: Acetic anhydride (23.4 ml) was added to the suspension of (R)-2-amino-3-hydroxypropanoic acid compound of formula-3 (20 grams) in acetic acid (300 ml) and stirred for 24 hours at 30-35° C. After completion of the reaction, acetic acid was removed by distillation followed by co-distillation with tetrahydrofuran. Isopropyl alcohol (60 ml) and methyltertiarybutylether (120 ml) was added to the obtained residue and stirred for 30 minutes. The obtained solid was filtered off and then solvent from the filtrate was distilled off completely under reduced pressure to get the title compound. was removed by distillation Isopropyl alcohol (60 ml) and methyltertiarybutylether (120 ml) was added to the obtained residue stirred for 30 minutes The obtained solid was filtered off solvent from the filtrate was distilled off completely under reduced pressure

Conditions: temp:30.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: Acetic anhydride (10.79 ml) was added to a suspension of D-serine (10 grams) in acetic acid (150 ml) and stirred at 25-35° C. After completion of the reaction, acetic acid was removed by distillation followed by co-distillation with tetrahydrofuran. Isopropyl alcohol (30 ml) and methyltertiarybutylether (60 ml) was added to the obtained residue and stirred for 30 minutes. The obtained solid was filtered off and then solvent from the filtrate was distilled off completely under reduced pressure to get the title compound. was removed by distillation Isopropyl alcohol (30 ml) and methyltertiarybutylether (60 ml) was added to the obtained residue stirred for 30 minutes The obtained solid was filtered off solvent from the filtrate was distilled off completely under reduced pressure

Conditions: temp:32.51; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: 4-methylmorpholine (7.3 ml) followed by isobutylchloroformate (12.35 ml) was added to a suspension of (R)-2-acetamido-3-hydroxypropanoic acid (7 grams) in tetrahydrofuran (147 ml) at −78 to −75° C., benzylamine (10.4 ml) was added to it and the reaction mixture temperature was raised to 30-35° C. then stirred for 30 minutes. The reaction mixture was filtered and the filtrate was distilled off under reduced pressure. The obtained residue was dissolved in methylene chloride (35 ml) and washed with aqueous hydrochloric acid followed by sodium carbonate and then with water. The solvent from the methylene chloride layer was distilled off completely under reduced pressure to get the title compound. The reaction mixture was filtered the filtrate was distilled off under reduced pressure The obtained residue was dissolved in methylene chloride (35 ml) washed with aqueous hydrochloric acid The solvent from the methylene chloride layer was distilled off completely under reduced pressure