title: Synthesis and antiallergy activity of [1,3,4]thiadiazolo[3,2-a]-1,2,3-triazolo[4,5-d]pyrimidin-9(3H)-one derivatives. II. 6-Alkyl- and 6-cycloalkylalkyl derivatives.
abstract: A series of 6-alkyl- or 6-(cycloalkylalkyl)-[1,3,4]thiadiazolo[3,2- a]-1,2,3-triazolo[4,5-d]pyrimidin-9(3H)-ones 1b--o was synthesized from the corresponding 1,3,4-thiadiazol-5-amines 3b--o and the antiallergic activities of the products were evaluated. Among the compounds 6-(2-cyclohexylethyl)- [1,3,4]thiadiazolo[3,2-a]-1,2,3-triazolo[4,5-d]pyrimidin-9(3H)-one 1h, whose X-ray crystallographic stereostructure is shown, was found to be a promising new antiallergic agent, which has low toxicity and dual activity as a leukotriene D4 receptor antagonist and as an orally active mast cell stabilizer.
authors.affiliation: Exploratory Research Laboratories III, Daiichi Pharmaceutical Co., Ltd., Tokyo, Japan.
authors.forename: S
authors.initials: S
authors.lastname: Yokohama
authors.forename: T
authors.initials: T
authors.lastname: Miwa
authors.forename: S
authors.initials: S
authors.lastname: Aibara
authors.forename: H
authors.initials: H
authors.lastname: Fujiwara
authors.forename: H
authors.initials: H
authors.lastname: Matsumoto
authors.forename: K
authors.initials: K
authors.lastname: Nakayama
authors.forename: T
authors.initials: T
authors.lastname: Iwamoto
authors.forename: M
authors.initials: M
authors.lastname: Mori
authors.forename: R
authors.initials: R
authors.lastname: Moroi
authors.forename: W
authors.initials: W
authors.lastname: Tsukada
mesh_terms: D000818:Animals; D005260:Female; D006168:Guinea Pigs; D006967:Hypersensitivity / Q000188:drug therapy*; D066298:In Vitro Techniques; D008168:Lung / Q000187:drug effects; D009119:Muscle Contraction / Q000187:drug effects; D010047:Ovalbumin / Q000276:immunology; D010323:Passive Cutaneous Anaphylaxis / Q000187:drug effects; D011743:Pyrimidines / Q000138:chemical synthesis* / Q000494:pharmacology; D051381:Rats; D017207:Rats, Sprague-Dawley; D013189:SRS-A / Q000037:antagonists & inhibitors; D013830:Thiadiazoles / Q000138:chemical synthesis* / Q000494:pharmacology; D014230:Triazoles / Q000138:chemical synthesis* / Q000494:pharmacology; D014961:X-Ray Diffraction
chemical_list: D011743:Pyrimidines; D013189:SRS-A; D013830:Thiadiazoles; D014230:Triazoles; C076052:DS 4574; D010047:Ovalbumin