Synthesis and antitussive activity of aminotetra- (and -hexa-) hydrodibenzofurans

The synthesis of a novel series of antitussive agents is described. Two series of amino-substituted tetra- and hexahydrodibenzofurans were prepared and examined for antitussive activity in the guinea pig after cough elicited by electrical stimulation of the vagus nerve. A significant level of activity, comparable with that of codeine, was found in the 4alpha-amino series. The 4-methylpiperazin-1-ylpropionamide (28) was found to be the most active of the compounds synthesized and was equipment with codeine. The effects of structural modification upon antitussive activity were investigated in numerous analogues but no enhancement of activity was achieved over that of 28.

Preparation of qualitative standard mixtures of polychlorinated dibenzo-rho-dioxins and dibenzofurans by ultraviolet and psi-irradiation of the octachloro compounds

High-resolution gas chromatography using an OV-17 glass capillary column and mass spectrometry were used to analyze uv-and psi-irradiated octachlorodibenzo-rho-dioxin and octachlorodibenzofuran. Under the conditions investigated, dechlorination of these compounds to lower chlorinated dibenzo-rho-dioxins and dibenzofurans appears to be the major reaction pathway. The resulting mixtures of penta-, hexa-and heptachloro compounds can be used as easily and safely prepared qualitative reference samples to determine gas chromatographic, mass spectrometric and other properties of individual components for which pure standards are not available.

Synthesis of spiro[isobenzofuran-1(3H),4'-piperidines] as potential central nervous system agents

Synthesis of 1'-methyl-3-phenylspiro[isobenzofuran-1(3H),4'-piperidine] (7a, HP 365) and the demethyl analogue 9a (HP 505) was prompted by recognition of an aminoalkyl(aryl)isobenzofuran moiety common to the antidepressants talopram (Lu 3-010) and trans-10,11-dihydro-5,10-epoxy-5-[3-(methylamino)propyl]-5H-dibenzo[a,d]cyclohepten-11-ol (MK-940). Convenient laboratory synthesis of 7a was provided by lithiation of 2-bromobenzhydryl methyl ether, followed by addition of 1-methyl-4-piperidone and acid-catalyzed cyclization. N-Dealkylation by standard methods afforded 9a. Synthesis of analogues was stimulated by discovery of marked inhibition of tetrabenazine-induced ptosis for lead compounds 7a and 9a. Optimal antitetrabenazine activity is associated with the 3-phenylspiro-[isobenzofuran-1(3H),4'-piperidine] moiety where nitrogen is basic. Modification of this moiety by introduction of large nitrogen substituents or a C-3 substituent greater than H significantly reduced antitetrabenazine activity. A series of analogues with aromatic substituents was investigated; however, few of these compounds were significantly more active than 7a and 9a. Compound 9a was selected for additional studies.

Synthesis and antibacterial and antifungal activities of alkyl and polyhalophenyl esters of benzo[b]-3-methyl-2-furancarbamic acid

Several alkyl and polyhalophenyl esters of benzo[b]-3-methyl-2-furancarbamic acid were prepared and tested for antifungal activity against Candida albicans, Penicillium notatum, and Aspergillus niger. The pentachlorophenyl ester was the most active substance and the only compound to show antibacterial activity against Staphylococcus aureus.

Comparative antilipidemic effects of various ethyl 5-substituted benzofuran-, 2,3-dihydrobenzofuran-, and 3(2H)-benzofuranone-2-carboxylate analogs of clofibrate in a triton hyperlipidemic rat model

The antilipidemic properties of certain benzofuran-, 2,3-dihydrobenzofuran-, and 3(2H)-benzofuranone-2-carboxylate analogs of clofibrate in a hyperlipidemic rat model are described. The hyperlipidemia was induced by intraperitoneal injection of Triton WR-1339. The results were analyzed in light of structural modifications as well as the lipid solubility of substituted compounds as assessed by a consideration of calculated log P values. Comparisons are made between the activity of these compounds and the activity of related cyclic analogs previously reported. Among the various compounds tested, only the 5-C1 and phenylsybstituted dihydrobenzofurans were selective against elevated serum cholesterol levels in this animal model. The data presented support the hypothesis that the cholesterol and triglyceride lowering activity of clofibrate related analogs in this animal model may be separated through a consideration of log P, conformational, and electronic changes. The proposal is advanced that relatively minor structural modification of clofibrate related analogs may lead to compounds which are not only selective in the Triton model but also to compounds which are likely to exert their effects by differing modes of action.

Antiinflammatory activity of some 2,3-dihydrobenzofuran-5-acetic acids and related compounds

A series of 2,3-dihydrobenzofuran-5-acetic acids and related compounds was prepared as potential antiinflammatory agents. As measured by the carrageenan-induced edema method for the preliminary screening test, introduction of a methyl group alpha to the acetic acid function enhanced the antiinflammatory activity, and alpha-(7-chloro-2,2-dimethyl-2,3-dihydrobenzofuran)-alpha-methyl-5-acetic acid (13a) showed the most potent activity in this series.

Chemistry and antibacterial activity of nitrobenzofurans

Thirteen 2-methylbenzofurans were synthesized and their antibacterial activity was investigated. 2-Methyl-3-nitrobenzofuran and analogs containing 7-NO2, 5-NO2, 7-Br, 7-CONH2, and 7-CF3 substituents are bacteriostatic. The spectrum of activity of these compounds is similar to nitrofurazone; however, a strain of E. coli Br which has increased resistance to nitrofurazone did not show increased resistance to 3,7-dinitro-2-methylbenzofuran (1). The 3-nitro-2-methylbenzofurans are labile in solution (T1/2 0.8-3.5 hr at 37 degrees, pH 7.0). The solvolysis product of 1 was identified as alpha,6-dinitro-o-cresol (15). The 3-nitrobenzofurans are more potent in minimal media than in Penassay broth. This greater potency can be abolished by addition of casamino acids and tryptophan to the minimal media.

9-Chloro-2,3-dihydro-5H-1,4-dioxepino(6,5-b)benzofuran, a novel antilipidemic agent structurally related to clofibrate

The synthesis and antilipidemic activity of 9-chloro-2,3-dihydro-5H-1,4-dioxepino[6,5-b]benzofuran (3), a novel enol lactone which is considerably more resistant to serum esterase hydrolysis than clofibrate (1), are discussed. Whereas both 3 and 1 reduced hypercholesterolemic and hypertriglyceridemic serum levels in the Triton WR-1339 induced hyperlipidemic Sprague-Dawley rat to normal, the hydrolysis product of 3, namely 5-chloro-3(2'-hydroxyethoxy)-2-benzofurancarboxylic acid (4), was found to be inactive. Further, 3 is comparable to the hydrolysis product of 1 when both were assessed for their ability to block norepinephrine (NE) induced lipolysis in vitro. 4 is inactive at comparable concentrations (5 times 10(-4)-10(-3) M). The antilipidemic action of 3 and 1 may, in part, be due to their ability to block NE-induced lipolysis.