摘要:
A process for the preparation of (S)-N,N'-bis�2-hydroxy-1-(hydroxymethyl)ethyl!-5-(2-acetoxy-propionylamino)-2,4,6-triiodo-isophthalamide, an intermediate useful for the synthesis of iopamidol, by reaction between L-5-(2-acetoxy-propionylamino)-2,4,6-triiiodoisophthaloyl dichloride and 2-amino-1 ,3-propanediol in N-methylpyrrolidone and in the presence of a base, is described.
摘要:
A process for purifying Iopamidol which uses a butanol as solvent is described. Iopamidol is obtained with high yields, also starting from aqueous solutions of the same and has characteristics in accordance with those required by pharmacopoeia.
摘要:
A crystallization process of crude 5-(2',4'-difluorophenyl)-salicylic acid from a mixture of an aromatic hydrocarbon and an aliphatic ketone for preparing 5-(2',4'-difluorophenyl)-salicylic acid in form II substantially pure is described.
摘要:
A process is described for the preparation of 2-methoxy-6-propionyl-naphthalene, an intermediate in the synthesis of naproxen.The process consists of Friedel-Crafts acylation of 2-methoxy-naphthalene, and obviates the drawbacks related to the use of nitrobenzene as solvent.
摘要:
A process is described for preparing an intermediate in the synthesis of naproxen.The intermediate, namely the methyl ester of S(+)-2-(5-bromo-6-methoxy-2-naphthyl)-propionic acid or of its 5-chloro analogue, is prepared by preferential crystallization from mixtures with its enantiomer.