反应详情

A suspension of 10.4 g of Z-Gln(Trt)-OH (20 mmol) in 180 ml of a 9:1 mixture of methanol and water and 20 ml of one-normal aqueous hydrochloric acid is hydrogenated at room temperature and under atmospheric pressure in the presence of 0.5 g of a 10% palladium on charcoal catalyst; after the uptake of hydrogen is complete the starting material has dissolved. The catalyst is filtered off and washed with methanol; the filtrate is concentrated to 200 g and, at 60°, 2.8 ml of triethylamine (20 mmol) are added, whereupon the product immediately starts to crystallize. The mixture is concentrated to 100 g and left to stand at about 4° for some time, and the crystals are filtered off and washed with a mixture of methanol and water until free of chloride. The H-Gln(Trt)-OH obtainable in this way contains 0.5 mole of water and melts at 233° (with decomposition).

1. dissolutionhas dissolved
2. filtrationThe catalyst is filtered off
3. washwashed with methanol
4. concentrationthe filtrate is concentrated to 200 g and, at 60°
5. customto crystallize
6. concentrationThe mixture is concentrated to 100 g
7. waitleft
8. customto stand at about 4° for some time
9. filtrationthe crystals are filtered off
10. washwashed with a mixture of methanol and water until free of chloride