反应详情

温度

70 °C

30 g (400 mmol) of glycine was suspended in 60 ml of H2O and heated to 70° C. 10M of NAOH was added with an autotitrator up to pH 8.5. Then, 22.4 g (136 mmol) of 4-chloro-3-methoxy-but-2E-enoic acid methyl ester was added at 70° to 75° C. The pH was kept constant at 8.5 by adding 10M of NAOH. After 1 hour, another 22.4 g (136 mmol) of 4-chloro-3-methoxy-but-2E-enoic acid methyl ester was added, and, after another hour, 22.4 g (136 mmol) of 4-chloromethoxy-but-3E-enoic acid methyl ester again was added. After the final addition, the reaction mixture was stirred for another 3.5 hours at 70° to 75° C. The consumption of 10M of NAOH was then 80.3 ml, which corresponded to 2 equivalents relative to the glycine used. The reaction mixture was cooled to room temperature and diluted with 40 ml of H2O. Then, the reaction mixture was adjusted to pH 1 with concentrated HCl. The product precipitated after a short time, was filtered off and washed with saturated NaCl solution. After drying, 70.9 g of product was obtained. 3.41 g of product was obtained from the mother liquor. The total yield was 84 percent. The crude product was recrystallized from isopropanol: 68 g was recrystallized from 450 ml of isopropanol. 47 g of product, which corresponded to an 87 percent yield, was obtained. The product contained less than 0.01 percent of Cl. Other data for the product was:

1. addition10M of NAOH was added with an autotitrator up to pH 8.5
2. additionby adding 10M of NAOH
3. waitafter another hour
4. additionAfter the final addition
5. customThe consumption of 10M of NAOH
6. temperatureThe reaction mixture was cooled to room temperature
7. additiondiluted with 40 ml of H2O
8. customThe product precipitated after a short time
9. filtrationwas filtered off
10. washwashed with saturated NaCl solution
11. customAfter drying