反应详情

5.835 g of methyl carbamate and 10.000 g of 2-oxo-4-(hydroxymethylphosphinyl)-butanoic acid were added to 17 mL of acetic acid to be suspended. After being dissolved by heating, 68 mL of toluene was added thereto and then the solution was refluxed with vigorous stirring. The internal temperature of the reaction solution was from 106 to 108 deg. C. Four hours later, dissipation of almost all the raw materials was confirmed by HPLC measurement. At this point, the area ratio of Z form to E form was 94:6. After removing about 42 mL of the solvent under a reduced pressure, followed by adding 23 mL of acetic acid, and then the resultant was stirred for 1 hour at 80 deg. C. The precipitate which was obtained by cooling the solution gradually to room temperature and stirring over-night, was filtered and then the filtrate was washed with acetic acid. After being washed with acetone, dried for 5 hours from 40 to 50 deg. C. under a reduced pressure, 9.931 g of the objective compound was obtained (75.4% yield, Z:E=99.6:0.4).

1. dissolutionAfter being dissolved
2. temperatureby heating
3. temperaturethe solution was refluxed with vigorous stirring
4. customwas from 106 to 108 deg. C
5. customFour hours
6. customAfter removing about 42 mL of the solvent under a reduced pressure
7. additionby adding 23 mL of acetic acid
8. customThe precipitate which was obtained
9. stirringstirring over-night
10. filtrationwas filtered
11. washthe filtrate was washed with acetic acid
12. washAfter being washed with acetone
13. customdried for 5 hours from 40 to 50 deg. C