N-Methylallylamine → 3-(Allyl-methyl-carbamoyl)-5-amino-2,4,6-triiodo-benzoyl chloride

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Reaction Steps

Typically 5-amino-2,4,6,triiodoisophthaloyl dichloride (1) (100 g, 168 mmol) was dissolved in anhydrous THF (500 ml), the N-methyl allylamine (25 ml) was dissolved in 50 ml THF, and added dropwise to the solution over 1 hour. The mixture was heated to 50 deg C. and stirred overnight. The crude mixture was analysed by LCMS and this confirmed that the reaction mixture contained the desired product, ‘bis-acid chloride’ and ‘bis-N-methyl-allylamide’. The reaction was also monitored by TLC (2% MeOH in DCM) on silica gel plates, bis-acid chloride had an Rf of ˜0.98, the mono-N-methylallylamide ˜0.73 and the bis-N-methylallylamide ˜0.25. Once the reaction was deemed complete, the solution was filtered, vacuumed to dryness, then dissolved in 500 ml of ethyl acetate this solution was then loaded onto silica and purified on a 750 g column using ethyl acetate (B) and petrol (A) (10%→100% B over ˜10 column volumes). The pure fractions were collected and identified by TLC, the desired fractions were then vacuumed to dryness. The structure was confirmed by 1H and 13C NMR and purity by LCMS.

Provenance & Evidence