A new series of 3-(3-pyridyl)acrylamides 16, 17, 19, and 26, and 5-(3-pyridyl)-2,4-pentadienamides 20-25 were prepared and evaluated for their antiallergic activity. Several of these compounds exhibited more potent inhibitory activities than the parent compound 1a [(E)-N-[4-[4-(diphenylmethyl)-1-piperazinyl]butyl]-3- (3-pyridyl)acrylamide] against the rat passive cutaneous anaphylaxis (PCA) reaction and the enzyme 5-lipoxygenase. Particularly, (E)-N-[4-[4-(diphenylmethyl)-1-piperazinyl]butyl]-3- (6-methyl-3-pyridyl)acrylamide (17p) showed an ED50 value of 3.3 mg/kg po in the rat PCA test, which was one-fifth of ketotifen and oxatomide. As compared with ketotifen and oxatomide, compound 17p (AL-3264) possessed a better balance of antiallergic properties due to inhibition of chemical mediator release, inhibition of 5-lipoxygenase, and antagonism of histamine.

A new series of oxopyridinecarboxamide derivatives 3a--g and 5a were synthesized and evaluated for their antiallergic activity. 1,4-Dihydro-7-methyl-4-oxo-1,8-naphthyridine-3-carboxamides 3a and 5a exhibited potent antiallergic activity (inhibitory rates of 80.7 and 88.3%, respectively, at 20 mg/kg, p.o.) in the rat passive cutaneous anaphylaxis (PCA) test and also exhibited much more potent in vitro inhibitory activity than caffeic acid against the enzyme 5-lipoxygenase (5-LO). Their in vitro antihistamine activity, however, was weaker than that of ketotifen. Compounds 3a and 5a are viewed as promising candidates for antiallergic agents.

No abstract

A new series of acrylamide derivatives (7-10) were synthesized. Antiallergic activity of these compounds was evaluated and their structure-activity relationships were examined. Compound 10d, N-[4-(4-diphenylmethyl-1-piperazinyl)butyl]-3-(3-pyridyl)acrylamid e, showed antiallergic activity equivalent or superior to that of ketotifen in the rat passive cutaneous anaphylaxis (PCA) test by oral administration. Compound 10d, unlike ketotifen, had more potent in vitro 5-lipoxygenase inhibitory activity than caffeic acid, whereas its in vitro antihistamine activity was weaker than that of ketotifen. In addition, its inhibitory activity against histamine release from rat mast cells was approximately two-thirds as potent as that of disodium cromoglycate (DSCG). Compound 10d is a promising agent for treating a variety of allergic diseases.

The heteroarylacrylic acids (I) are coupled with the diamines (II) in the presence of a carbodiimide to produce the acrylic amides (III).