Water → t-Butoxycarbonylglycyl thyroxine methyl ester

Participants

Reaction Steps

To the aforesaid Boc-Gly-OSu solution the thyroxine methyl ester solution was added while ice cooling. After permitting the same to warm to room temperature, the mixture was stirred for 1.5 hr. After letting the reaction mixture stand overnight, 25 ml. of distilled water and 50 ml. of ethyl acetate were added thereto and the mixture was extracted with ethyl acetate. The extraction was repeated three times using 25 ml. of ethyl acetate. The ethyl acetate layers were combined and dried over anhydrous magnesium sulfate. The liquid was concentrated using a rotary evaporator and subjected to gel chromatography using a column filled with Sephadex LH-20 (made by Pharmacia Co., Ltd.). As the solvent, a mixture obtained by mixing acetone and methanol in a proportion of 4:1 (volume) was used. While confirming by TLC, the objective fraction was taken and concentrated under reduced pressure followed by crystallization. The product was obtained in an amount of 950 mg. (yield 82.5%).

Provenance & Evidence