Endogenous natriuretic factors. 5. Synthesis and biological activity of a natriuretic metabolite of diltiazem and its derivatives

Benzyl thioether formation merging copper catalysis

A novel copper-catalyzed thioetherification reaction has been developed to afford benzyl thioethers in moderate to excellent yields. Under the mild and easy-to-operate conditions, a variety of thioethers are efficiently prepared from readily available benzyl alcohols (primary, secondary, and tertiary) and thiols in the presence of Cu(OTf)2 as the Lewis acid catalysis. This C-S bond formation protocol furnishes exceptional chemoselectivity, and the preliminary mechanism studies show that the reaction should proceed through a Lewis-acid-mediated SN1-type nucleophilic attack of the carbocations formed in situ.

Synthesis of Thiazine and Thiazepine Derivatives from (Z)-2-Cyano-3-Mercapto-3-(Phenylamino)Acrylamide

The reaction of ( Z)-2-cyano-3-mercapto-3-(phenylamino)acrylamide with teteracyanoethylene and 2-dicyanomethyleneindan-1,3-dione gave thiazine derivatives. While its reaction with 1,4-naphthoquinone, 2,3-dicyano-1,4-naphthoquinone and/or 2,3-dichloro-1,4-naphthoquinone led to the formation of the corresponding napthothiazepine derivatives.

Syntheses and Biological Activities of Chalcone and 1,5-Benzothiazepine Derivatives: Promising New Free-Radical Scavengers, and Esterase, Urease, and?-Glucosidase Inhibitors

A series of 2,4-diaryl-2,3,4,5-tetrahydro- (36-40) and 2,4-diaryl-2,3-dihydro-1,5-benzothiazepines (25-35) have been synthesized from the corresponding chalcones 1-24. Both the benzothiazepines and chalcones were evaluated as DPPH free-radical scavengers and as inhibitors of cholinesterases, urease, and alpha-glucosidase. Compounds 2, 5, 6, 7, 10, 13, 18, 21, 36a, 37a, 37b, and 39a showed significant cholinesterase inhibiting activities. Among the 15 dihydro-1,5-benzothiazepines, 26, 32, and 35 exhibited significant radical-scavenging activities; and six tetrahydro-1,5-benzothiazepines (35, 36a, 36b, 37a, 37b, and 39a) were found to be inhibitors of AChE and BChE. Compounds 22, 25, 26, 33, 35, 36a, 37b, and 39a inhibited urease, and 25 and 27-31 were found to be potent inhibitors of alpha-glucosidase.

A novel dilithiation approach to 3,4-dihydro-2H-1,3-benzothiazines, 3,4-Dihydro-2H-1,3-benzoxazines, and 2,3,4,5-tetrahydro-1,3-benzothiazepines

3,4-Dihydro-2H-1,3-benzothiazines 4, 3,4-dihydro-2H-1,3-benzoxazines 9, and 2,3,4,5-tetrahydro-1,3-benzothiazepines 6 were synthesized by directed ortho-lithiation of thiophenols and phenols and by side-chain lithiation of substituted thiophenols, respectively, in one-pot by reacting with N,N-bis[(benzotriazol-1-yl)methyl]amines 3 as 1,3-biselectrophile synthons.

Syntheses of 1,4-benzothiazepines and 1,4-benzoxazepines via cyclizations of 1-[2-arylthio(oxy)ethyl]-5-benzotriazolyl-2-pyrrolidinones and 3-benzotriazolyl-2-[2-arylthio(oxy)ethyl]-1-isoindolinones

1-[2-Arylthio(oxy)ethyl]-5-benzotriazolyl-2-pyrrolidinones 6a-e, 12 and 3-benzotriazolyl-2-[2-arylthio(oxy)ethyl]-1-isoindolinones 9a-f, 14 are readily available from reactions of benzotriazole (4), 2-(arylsulfanyl)ethylamines 3, or 2-phenoxyethylamine (11) with 2,5-dimethoxy-2,5-dihydrofuran (5) or 2-formylbenzoic acid (8). Lewis acid mediated cyclizations of 6 and 9 produced novel 1,4-benzothiazepines 7a-e and 10a-f, respectively. Cyclizations of 12 and 14 gave 1,4-benzoxazepines 13 and 15, respectively.