(2S)-2-(methylamino)butanedioic acid

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

Procedure: 10.7 g of N-methylaspartic acid was placed in a 250 ml round-bottom flask, and 100 ml of water was added to the flask and stirred for 30 minutes by using a magnetic stirrer. 7.12 g of concentrate 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 100 ml of toluene to further remove the water and dried under vacuum to obtain 17 g of N-methylaspartic acid sulfate as yellow oil (Yield: 95.3%). under stirring stirred for additional 2 hours After the reaction the reaction solution was concentrated azeotroped with 100 ml of toluene to further remove the water dried under vacuum

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

Procedure: 10.7 g of N-methylaspartic acid was placed in a 250 ml round-bottom flask, and 100 ml of water was added to the flask and stirred for 30 minutes by using a magnetic stirrer. 7.12 g of concentrate 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 100 ml of toluene to further remove the water and dried under vacuum to obtain 17 g of N-methylaspartic acid sulfate as yellow oil (Yield: 95.3%). under stirring stirred for additional 2 hours After the reaction the reaction solution was concentrated azeotroped with 100 ml of toluene to further remove the water dried under vacuum

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

Procedure: 10.7 g of N-methylaspartic acid was placed in a 250 ml round-bottom flask, and 100 ml of water was added to the flask and stirred for 30 minutes by using a magnetic stirrer. 7.12 g of concentrate 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 100 ml of toluene to further remove the water and dried under vacuum to obtain 17 g of N-methylaspartic acid sulfate as yellow oil (Yield: 95.3%). under stirring stirred for additional 2 hours After the reaction the reaction solution was concentrated azeotroped with 100 ml of toluene to further remove the water dried under vacuum