Preparation of 5-amino-isophthalamides
AssigneeAmersha, Health AS
InventorsEdward David Parady, Karl Olaf Gelotte
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Abstract
A process for preparing 5-amino-N,N′-bis(R)isophthalamides, where A is 2,3-dihydroxypropyl or 1,3-dihydroxyisopropyl, useful as intermediates in preparing iodinated diagnostic agents, which comprises reacting a di-lower-alkyl 5-nitroisophthalate with a compound of the formula RNH2 in the presence of a basic catalyst and without isolating the intermediate 5-nitro-N,N′-bis(R)isophthalamide, catalytically hydrogenating the latter.
Claims7
The process for preparing a compound of the formula
- where R is CH2CH(OH)CH2OH or CH(CH2OH)2, which comprises reacting a di-lower-alkyl 5-nitroisophthalate with at least two molar equivalents of a compound of the formula RNH2 in a solvent comprising a lower-aliphatic alcohol containing a basic catalyst to obtain a solution containing 5-nitro-N,N′-bis(R)isophthalamide, and, without isolating the latter, catalytically hydrogenating said solution to obtain a solution of 5-amino-N,N′-bis(R)isophthalamide.
The process for preparing 5-amino-N,N′-bis(2,3-dihydroxypropyl)isophthalamide which comprises heating at reflux temperature a solution of dimethyl 5-nitroisophthalate and about 2.1 molar equivalents of 3-amino-1,2-propanediol in 2-methoxyethanol containing a catalytic amount of dissolved sodium until essentially all of the dimethyl 5-nitroisophthalate has been consumed, and hydrogenating said mixture in the presence of a palladium-on-carbon catalyst until reduction of the nitro group to an amino group is essentially complete.
Dependencies are inferred from the claim text.