反应详情

The hydrogenation of 4-cyano-2-hydroxy-2-phosphonobutanoic acid is carried out using the hydrogenation technique of Freifelder (J. Am. Chem. Soc., 8, 2386 (1960)). The cyano compound (2.09 g; 0.01 mole) is placed in 20 ml of 10% methanolic ammonia. Rhodium on alumina (5%) catalyst (0.5 g) is added, and the mixture is hydrogenated at 40 PSI on a Parr apparatus for several hours (until uptake of hydrogen is complete). The catalyst is filtered off, and the filtrate is evaporated dry. The residue treated with cation exchange resin in H+ form to convert the material to acid form. The solution containing it is evaporated to dryness under vacuum. The product is purified by dissolving the residue in water, adding ethanol to give a precipitate, and collecting the solids by filtration. Further purification is accomplished by again recrystallizing from water/ethanol.

1. waitthe mixture is hydrogenated at 40 PSI on a Parr apparatus for several hours
2. filtrationThe catalyst is filtered off
3. customthe filtrate is evaporated
4. customdry
5. additionThe residue treated with cation exchange resin in H+ form
6. additionThe solution containing it
7. customis evaporated to dryness under vacuum
8. customThe product is purified
9. dissolutionby dissolving the residue in water
10. additionadding ethanol
11. customto give a precipitate
12. customcollecting the solids
13. filtrationby filtration
14. customFurther purification
15. customby again recrystallizing from water/ethanol