5-Aminosalicylic Acid → Boc-Lys(Z)-OH

Participants

Reaction Steps

70.4 g (0.14 mole) of BOC-L-Lys(Z)-SDP (m.w. 502.6) was dissolved in 200 ml of THF, which was then added dropwise to a solution of 21.4 g (0.14 mole) of 5-aminosalicyclic acid (m.w. 153.14) in 187 ml of 1.5 N NEM/DMF solution at 0°-5° C., and the reaction was effected at normal temperature for 18 hours, after which the reaction mixture was concentrated to 100-200 ml, 1600 ml of ether/ethyl acetate (50 v/50 v) was added, the mixture was washed with 1000 ml of cold 5% HCl three times and then with 1000 ml of saturated aqueous NaCl twice, active carbon was added, dried on magnesium sulfate, and the solvent was distilled off, to obtain, by recystallization from ether/isopropyl ether, 8.9 g (yield 55%) of crystalline BOC-L-Lys(Z)-CHA (m.w. 515.6) of m.p. 102°-105° C.

Provenance & Evidence