Phthalyl group

The structure of sulfonamides is shown for representative purposes. Among the several thousand compounds in existence, about 25-30 have found widespread use. Sulfanilamide itself is, by present-day standards, very inactive. It was the development of heterocyclic derivatives that produced the highly potent sulfathiazole (9.90). When a succinyl or phthalyl group is attached to the aniline nitrogen, the inactive acylanilide derivatives will not be absorbed from the intestinal tract. Slow deacylation by intestinal... 

PVA is further modified to obtain polyvinylacetatephthalate (PVAcP), which is used in enteric coatings. PVAcP is prepared from the reaction of partially hydrolyzed polyvinyl alcohol, sodium acetate and phthalic anhydride. It consists of 55 to 62% of phthalyl groups. The PVA used is a low molecular weight grade with 87 to 89 mole% hydrolyzed. Since only vinyl alcohol portions of the partially hydrolyzed PVA are phthalated, the acetyl content remains constant before and after the reaction. 

Fig. 12. Introduction (a) and removal (b) of the phthalyl group at amino-nitrogen...

N-Aziridinylphosphorus compounds. A soln. of methyl 3- m-[bis-(l-aziridinyl)-phosphinylamino]phenyl)-N-phthaloyl-DL-alanate and 1 mole of hydrazine hydrate in methanol stirred 4 days at room temp. crude methyl 3-(m-[bis-(l-aziridinyl)phosphinylamino]phenyl)-DL-alanate (Y 89%) dissolved in methanol, treated with 1 mole of methanolic ANa-methoxide and some water, allowed to stand 20 hrs. at room temp. -> Na-3-(m-[bis-(l-aziridinyl)phosphinylamino]-phenyl)-DL-alanate (Y 83%).—Aziridine derivatives such as the above ones are quite sensitive to ring cleavage by acids. F. e. s. A. P. Martinez, W. W. Lee, and L. Goodman, J. Med. Ghem. 7, 224 (1964) selective removal of the phthalyl group in dimethylformamide, peptides, s. M. Bodanszky et al.. Am. Soc. 86, 4452 (1964) in isopropanol s. A. F. Rosenthal and M. Pousada, R. 84, 833 (1965). 

Another essentially non-hydrolytic method for cleaving urethans and ureas has been developed by Ing and Manske. The carboalkoxy group of the urethan is first replaced by the phthalyl group, usually in excellent yields, by fusion with phthalic anhydride. The resulting... 

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