Dimethylformamide → N-methyl-N-carboxymethylglycylthyroxine methyl ester

Beteiligte Stoffe

Reaktionsschritte

In 15 ml. of dimethylformamide (DMF) was dissolved 2 g. of thyroxine methyl ester hydrochloride, and to this was added 500 μl. of triethylamine. After 10 min., 0.55 g. of N-methyliminodiacetic acid in 5 ml. of THF was added to the resulting solution. This reaction mixture was concentrated in a rotary evaporator, and a residue was dissolved in 50 ml. of THF. After addition of 150 ml. of ethyl acetate, the mixture was shaken. The ethyl acetate phase was taken up and washed successively with three portions of distilled water and one portion of a saturated aqueous saline solution. The ethyl acetate phase was dried over anhydrous sodium sulfate, and the supernatant was concentrated in a rotary evaporator. To the residue were successively added 20 ml. of THF and a small amount of n-hexane. The produced precipitate was collected by filtration with suction to obtain a white crystalline product. The product was dried in a vacuum desiccator to give white crystals; yield 69%.

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