benzyl N-[(2S)-1-hydrazinyl-3-hydroxy-1-oxopropan-2-yl]carbamate

Conditions: temp:-15.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: 5.06 Grams of Z-Ser-NHNH2 was dissolved in 50 ml of dimethylformamide with 6.66 ml of 6N-hydrochloric acid/dioxane, the solution was cooled to -15° C. then 2.68 ml of isoamyl nitrite was added thereto, and the mixture was stirred for 5 minutes. Next, 5.60 ml of triethylamine was added to neutralize the reaction mixture. This reaction mixture was added to 30 ml of dimethylformamide solution containing 3.11 g of H-Ser-OMe.HCl and 2.80 ml of triethylamine, then this mixture was stirred at 4° C. for 20 hours. Dimethylformamide was removed by distillation, the residue obtained was extracted with ethyl acetate, the extract was washed with water and was dried with anhydrous sodium sulfate. After removal of ethyl acetate by distillation, the residue was crystallized by adding ether, reprecipitated from ethyl acetate-ether to obtain 3.75 g of Z-Ser-Ser-OMe. this mixture was stirred at 4° C. for 20 hours Dimethylformamide was removed by distillation the residue obtained was extracted with ethyl acetate the extract was washed with water was dried with anhydrous sodium sulfate After removal of ethyl acetate by distillation the residue was crystallized by adding ether reprecipitated from ethyl acetate-ether

Conditions: temp:-15.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: 3.19 Grams of Z-Ser-NHNH2 was dissolved in 25 ml of dimethylformamide, and 6.30 ml of 6N-hydrochloric acid/dioxane was added to the solution, cooled to -15° C., then 1.69 ml of isoamyl nitrite was added thereto. After the reaction mixture shows a negative reaction in hydrazine-test, 1.76 ml of a cold dimethylformamide solution with 5.29 ml of triethylamine was added drop by drop in small amount to neutralize the reaction mixture. This reaction mixture containing an azide product was added to 20 ml of a cold dimethylformamide solution containing H-Leu-Ser-OCH3.HCl obtained in the above-mentioned step 14(a) and 1.60 ml of triethylamine, and the whole mixture was stirred at -10° to -15° C. for 2 hours, next at 4° C. for 18 hours. Dimethylformamide was removed by distillation under a reduced pressure, the residue obtained was solidified by adding water, reprecipitated from methanol-ethyl acetate to obtain 4.11 g of the desired product. was added drop by drop in small amount Dimethylformamide was removed by distillation under a reduced pressure the residue obtained reprecipitated from methanol-ethyl acetate

Conditions: temp:-15.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: 2.54 Grams of Z-Ser-NHNH2 was dissolved in 20 ml of dimethylformamide, and 5.00 ml of 6N-hydrochloric acid/dioxane was added thereto and the mixture was cooled to -15° C., then 1.34 ml of isoamyl nitrite was added under stirring condition. After the reaction mixture shows a negative reaction in hydrazine test, then a cold solution of 1.40 ml of dimethylformamide with 4.20 ml of triethylamine was added drop by drop in small amounts to neutralize the reaction mixture. This reaction mixture containing the azide was added to a 15 ml of a cold dimethylformamide solution containing 1.96 g of H-Leu-OC2H5.HCl and 1.40 ml of triethylamine, then whole mixture was stirred at -10° to -15° C. for 2 hours and at 4° C. for 20 hours. Dimethylformamide was removed by distillation under a reduced pressure and the residue thus obtained was extracted with ethyl acetate, then the ethyl acetate layer was washed with 1N-citric acid, a saturated aqueous solution of sodium chloride, a saturated aqueous solution of sodium hydrogencarbonate and a saturated aqueous solution of sodium chloride in this order and dried with anhydrous sodium sulfate then ethyl acetate was removed by distillation under a reduced pressure. To the residue thus obtained was added petroleum ether and washed by decantation. The oily substance obtained was dried under a reduced pressure in a desiccator, and the dried product was dissolved in 50 ml of methanol and 2.50 ml of 100% hydrazine monohydrate was added under ice-cooled condition, then the reaction product was allowed to stand at a room temperature for 20 hours, then methanol was removed by distillation under a reduced pressure. The residue thus obtained was solidified by adding ethyl ether and was dried in a desiccator. The dried product was washed with water to remove an excess of hydrazine monohydrate and reprecipitated from methanol-ethyl acetate to obtain 2.68 g of the desired product. whole mixture was stirred at -10° to -15° C. for 2 hours and at 4° C. for 20 hours Dimethylformamide was removed by distillation under a reduced pressure the residue thus obtained was extracted with ethyl acetate the ethyl acetate layer was washed with 1N-citric acid a saturated aqueous solution of sodium chloride, a saturated aqueous solution of sodium hydrogencarbonate and a saturated aqueous solution of sodium chloride in this order and dried with anhydrous sodium sulfate ethyl acetate was removed by distillation under a reduced pressure To the residue thus obtained washed by decantation The oily substance obtained was dried under a reduced pressure in a desiccator the dried product was dissolved in 50 ml of methanol 2.50 ml of 100% hydrazine monohydrate was added under ice- cooled condition methanol was removed by distillation under a reduced pressure The residue thus obtained was dried in a desiccator The dried product was washed with water to remove an excess of hydrazine monohydrate reprecipitated from methanol-ethyl acetate

Conditions: temp:-15.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: 2.13 Grams of Z-Ser-NHNH2 was dissolved in 20 ml of DMF and 4.20 ml of 6N-hydrochloric acid/dioxane was further added, then the mixture was cooled to -15° C., 1.13 ml of isoamyl nitrite was added under stirring. After the reaction mixture shows negative reaction in hydrazid test, then a cold solution of 3.53 ml of triethylamine with 1.20 ml of DMF was added dropwise to neutralize the reaction mixture. This mixture containing the azide was added to a cold DMF solution of H-Lys(Tos)-Glu-OH obtained in above-mentioned step 2(a) with 1.96 ml of triethylamine, then this mixture was stirred at -10° to -15° C. for 2 hours and at 4° C. for 20 hours. Dimethylformamide was removed by distillation, the residue thus obtained was extracted with ethyl acetate, then the ethyl acetate layer was washed with 1N-citric acid and a saturated aqueous solution of sodium chloride, then dried with anhydrous sodium sulfate, and ethyl acetate was removed by distillation under a reduced pressure. The residue thus obtained was solidified by adding ethyl ether and reprecipitated from ethyl acetate-ether to obtain 4.14 g of the desired product. this mixture was stirred at -10° to -15° C. for 2 hours and at 4° C. for 20 hours Dimethylformamide was removed by distillation the residue thus obtained was extracted with ethyl acetate the ethyl acetate layer was washed with 1N-citric acid a saturated aqueous solution of sodium chloride, then dried with anhydrous sodium sulfate, and ethyl acetate was removed by distillation under a reduced pressure The residue thus obtained reprecipitated from ethyl acetate-ether

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

Procedure: 2.48 Grams of Z-Ser-NHNH2 was dissolved in 20 ml of dimethylformamide and 4.89 ml of N-hydrochloric acid/dioxane, after cooled the reaction mixture to -15° C., then 1.31 ml of isoamyl nitrite was added thereto and stirred for 5 minutes. Then 4.11 ml of triethylamine was added to the reaction mixture to neutralize the mixture. This reaction mixture was added into 10 ml of a dimethylformamide solution containing the above-mentioned H-Leu-Gly-OC2H5 and 1.24 ml of triethylamine and stirred at 4° C. for 20 hours. After removal of dimethylformamide by distillation, the residue thus obtained was extracted with ethyl acetate, and the extract was washed with 1N-citric acid and a saturated aqueous solution of sodium chloride in this order, then the extract was dried with anhydrous magnesium sulfate. After removal of ethyl acetate, reprecipitated from ethyl acetate to obtain 2.64 g of Z-Ser-Leu-Gly-OC2H5. stirred at 4° C. for 20 hours After removal of dimethylformamide by distillation the residue thus obtained was extracted with ethyl acetate the extract was washed with 1N-citric acid a saturated aqueous solution of sodium chloride in this order, then the extract was dried with anhydrous magnesium sulfate After removal of ethyl acetate reprecipitated from ethyl acetate