(2S)-2-(methylamino)pentanedioic acid

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

Procedure: 10.65 g of N-methylglutamic acid was placed in a 250 ml round-bottom flask, and 100 ml of water was added to the flask and stirred by using a magnetic stirrer for 30 minutes. Then, 6.38 g of concentrated sulfuric acid (concentration: 98%) was slowly dropped into the flask under stirring, and stirred for additional 2 hours after dropping. After the reaction, the reaction solution was concentrated, azeotroped with toluene to further remove the water and dried under vacuum to obtain 16.5 g of N-methylglutamic acid sulfate as yellow oil (Yield: 97.7%). for 30 minutes under stirring stirred for additional 2 hours After the reaction the reaction solution was concentrated azeotroped with toluene to further remove the water dried under vacuum

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

Procedure: N-Methyl-L-glutamic acid (3.2 g) was added to water (50 ml) and the pH of the solution adjusted to 9 with solid sodium bicarbonate. The solution was cooled to 0° C. and stirred vigorously, while benzyl chloroformate (9 ml) was added dropwise over 20 min. The mixture was stirred for a further 2 h at 0° C. and an additional 2 h at room temperature, then extracted with diethyl ether (2×100 ml). The aqueous solution was then acidified to pH 3 with 5N HCl and the product isolated by extraction with ethyl acetate (2×100 ml). The pooled organic extracts were dried over anhydrous sodium sulphate and the solvent concentrated in vacuo to give a yellow oil, which crystallised on standing. Recrystallisation from water afforded N-(benzyloxycarbonyl)-N-methyl-L-glutamic acid (2.26 g), m.p. 97°-98° C. was added dropwise over 20 min extracted with diethyl ether (2×100 ml) the product isolated by extraction with ethyl acetate (2×100 ml) The pooled organic extracts were dried over anhydrous sodium sulphate the solvent concentrated in vacuo to give a yellow oil, which crystallised Recrystallisation from water

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

Procedure: N-Methyl-L-glutamic acid (3.2 g) was added to water (50 ml) and the pH of the solution adjusted to 9 with solid sodium bicarbonate. The solution was cooled to 0° C. and stirred vigorously, while benzyl chloroformate (9 ml) was added dropwise over 20 min. The mixture was stirred for a further 2 h at 0° C. and an additional 2 h at room temperature, then extracted with diethyl ether (2×100 ml). The aqueous solution was then acidified to pH 3 with 5N HCl and the product isolated by extraction with ethyl acetate (2×100 ml). The pooled organic extracts were dried over anhydrous sodium sulphate and the solvent concentrated in vacuo to give a yellow oil, which crystallised on standing. Recrystallisation from water afforded N-(benzyloxycarbonyl)-N-methyl-L-glutamic acid (2.26 g), m.p. 97°-98° C. was added dropwise over 20 min extracted with diethyl ether (2×100 ml) the product isolated by extraction with ethyl acetate (2×100 ml) The pooled organic extracts were dried over anhydrous sodium sulphate the solvent concentrated in vacuo to give a yellow oil, which crystallised Recrystallisation from water

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

Procedure: 10.65 g of N-methylglutamic acid was placed in a 250 ml round-bottom flask, and 100 ml of water was added to the flask and stirred by using a magnetic stirrer for 30 minutes. Then, 6.38 g of concentrated sulfuric acid (concentration: 98%) was slowly dropped into the flask under stirring, and stirred for additional 2 hours after dropping. After the reaction, the reaction solution was concentrated, azeotroped with toluene to further remove the water and dried under vacuum to obtain 16.5 g of N-methylglutamic acid sulfate as yellow oil (Yield: 97.7%). for 30 minutes under stirring stirred for additional 2 hours After the reaction the reaction solution was concentrated azeotroped with toluene to further remove the water dried under vacuum

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

Procedure: 10.65 g of N-methylglutamic acid was placed in a 250 ml round-bottom flask, and 100 ml of water was added to the flask and stirred by using a magnetic stirrer for 30 minutes. Then, 6.38 g of concentrated sulfuric acid (concentration: 98%) was slowly dropped into the flask under stirring, and stirred for additional 2 hours after dropping. After the reaction, the reaction solution was concentrated, azeotroped with toluene to further remove the water and dried under vacuum to obtain 16.5 g of N-methylglutamic acid sulfate as yellow oil (Yield: 97.7%). for 30 minutes under stirring stirred for additional 2 hours After the reaction the reaction solution was concentrated azeotroped with toluene to further remove the water dried under vacuum

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

Procedure: N-Methyl-L-glutamic acid (3.2 g) was added to water (50 ml) and the pH of the solution adjusted to 9 with solid sodium bicarbonate. The solution was cooled to 0° C. and stirred vigorously, while benzyl chloroformate (9 ml) was added dropwise over 20 min. The mixture was stirred for a further 2 h at 0° C. and an additional 2 h at room temperature, then extracted with diethyl ether (2×100 ml). The aqueous solution was then acidified to pH 3 with 5N HCl and the product isolated by extraction with ethyl acetate (2×100 ml). The pooled organic extracts were dried over anhydrous sodium sulphate and the solvent concentrated in vacuo to give a yellow oil, which crystallised on standing. Recrystallisation from water afforded N-(benzyloxycarbonyl)-N-methyl-L-glutamic acid (2.26 g), m.p. 97°-98° C. was added dropwise over 20 min extracted with diethyl ether (2×100 ml) the product isolated by extraction with ethyl acetate (2×100 ml) The pooled organic extracts were dried over anhydrous sodium sulphate the solvent concentrated in vacuo to give a yellow oil, which crystallised Recrystallisation from water