3-Amino-1,2-propanediol → N1,N3-Bis(2,3-dihydroxypropyl)-5-nitro-1,3-benzenedicarboxamide

Beteiligte Stoffe

Reaktionsschritte

Dimethyl 5-nitro-isophthalate and 2.4 molar equivalents of 1-amino-2,3-propanediol were refluxed in methanol for twenty hours and the resulting 5-nitro-N,N′-bis(2,3-dihydroxypropyl)isophthalamide was isolated in 84% yield. The latter compound was suspended in aqueous hydrochloric acid and hydrogenated in the presence of a palladium oxide/charcoal catalyst. The resulting 5-amino-N,N′-bis(2,3-dihydroxypropyl)-isophthalamide was not isolated but the acid solution containing it was iodinated with sodium iodine dichloride to obtain 5-amino-2,4,6-triiodo- N,N′-bis(2,3-dihydroxypropyl)isophthalamide in 71% yield from the nitro compound (over-all yield of 59.5% from dimethyl 5-nitroisophthalate). Subsequent reactions are described for the preparation of 5-[N-(2,3-dihydroxy-propyl)acetamido]-2,4,6 triiodo-N,N′-bis(2,3-dihydroxypropyl)isophthalamide, useful as an X-ray contrast agent.

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