A sulfoxide-based ring annelation approach to fused, many-membered ring N,S-heterocycles

An approach to many-membered ring N,S-heterocycles involving sulfoxide electrophilic sulfenylation (SES) followed by ring expansion of the derived sulfonium salt intermediate (in situ) is illustrated for 9- and 10-membered- ring compounds. Treatment of readily prepared sulfoxides 10a, 10b, 18a, 18b, 23a, and 23b with triflic anhydride (pyridine, CH2Cl2, 0 °C) provides heterocycles 13a (65%), 13b (60%), 19a (67%), 19b (67%), 24a (42%), and 24b (80%), respectively. Sulfoxides 5a and 5b, under several different conditions, give only the Pummerer dehydration products 6a and 6b, respectively. Diastereomeric sulfoxides 18a\u27 and 18b\u27, upon treatment with triflic anhydride, do not produce clean product mixtures or any of the desired heterocyclic products but, upon heating in toluene, are converted to the more stable isomers 18a and 18b, respectively. Conducting this isomerization in the presence of 2-mercaptobenzothiazole produces a disulfide indicative of the intermediacy of a sulfenic acid. However, the importance of sulfenic acid derivatives in the SES process leading to many-membered ring heterocycles remains to be determined

Reactions of benzyl aryl sulfides with excess active halogen reagents

1,2,3-Tribromopyrrolo[1,2-b][1,2]benzothiazin-10-one (2) is produced from 2-[2-(benzylthio)benzoyl]-pyrrole (1) when treated with excess (5 equiv) NBS in CHCl3. With NCS, a mixture is obtained in which di- and trichloropyrrolo[1,2-b][1,2]benzothiazin-10-ones are present. If ethanol is present in the NCS reaction, compound 4 is formed as the major product. Further, compound 3 is also formed by the reaction of compound 1 or the corresponding disulfide with excess SOCl2. A novel route to alkyl arenesulfinic esters is also reported. Treatment of a benzyl aryl sulfide with excess (5 equiv) NCS in the presence of an n-alkyl alcohol (7 equiv) produces an n-alkyl arenesulfinic ester in good yield. An arenesulfonyl chloride is the major product in the presence of benzyl alcohol

fused pyrazole synthesis by n-n bond formation: The pyrazolo [5,1-b] benzothiazole system

Treatment of (benzothiazol-2-yl)acetone oxime 1 with excess trifluoroacetic anhydride (TFAA) at room temperature produces 2-methyl-3-trifluoroacetylpyrazoIo[5, l-Z\u3e ]benzothiazole 11 in 71-92 % yield depending on the purity of the oxime. Compound 11 is reduced by NaBHi to the corresponding alcohol 12 and hydrolyzed to the corresponding carboxylic acid 13 under alkaline conditions. Other reagents commonly used to promote Beckmann rearrangement of oximes cause only decomposition of 1 to intractable materials. © 2011 by Walter de Gruyter GmbH & Co. All rights reserved

1-[(1,3-Dihydro-2-benzothienyl)acetyl]-1H-Indole S-oxide

The title compound, C18H15NO2S, consists of two heterocycles, namely an indole and a 1,3-dihydro-2- benzothienyl S-oxide moiety, connected by an acetyl bridge. An S - O distance of 1.5007 (15) Å was observed and the two C - S distances differ, with S - CH2 = 1.8217 (16) Àand S - CH= 1.8516 (16) Å

2-Cyanamidothiazoles from 3-propynylthio-1,2,4-triazoles

3-Allylthioallyl triazoles (5) rearrange to N-allyl derivatives (6) while 3-(2-propynyl) derivatives (2) provide 4,5-disubstituted 2- cyanamidothiazoles (9) in refluxing p-xylene. At lower temperatures N- allenyl derivatives (8) may be isolated and converted independently to 9. Intermediate allenes exhibit sigmatropic inversion of substituents characteristic of Claisen rearrangement

A Five-miRNA Panel Identified From a Multicentric Case–control Study Serves as a Novel Diagnostic Tool for Ethnically Diverse Non-small-cell Lung Cancer Patients

Circulating microRNAs (miRNAs) are promising biomarkers for cancer detection. However, multiethnic and multicentric studies of non-small-cell lung cancer (NSCLC) are lacking. We recruited 221 NSCLC patients, 161 controls and 56 benign nodules from both China and America. Initial miRNA screening was performed using the TaqMan Low Density Array followed by confirming individually by RT-qPCR in Chinese cohorts. Finally, we performed a blind trial from an American cohort to validate our findings. RT-qPCR confirmed that miR-483-5p, miR-193a-3p, miR-25, miR-214 and miR-7 were significantly elevated in patients compared to controls. The areas under the curve (AUCs) of the ROC curve of this five-serum miRNA panel were 0.976 (95% CI, 0.939–1.0; P < 0.0001) and 0.823 (95% CI, 0.75–0.896; P < 0.0001) for the two confirmation sets, respectively. In the blind trial, the panel correctly classified 95% NSCLC cases and 84% controls from the American cohort. Most importantly, the panel was capable of distinguishing NSCLC from benign nodules with an AUC of 0.979 (95% CI, 0.959–1.0) in the American cohort and allowed correct prediction of 86% and 95% stage I–II tumors in the Chinese and American cohorts, respectively. This serum miRNA panel holds the potential for diagnosing ethnically diverse NSCLC patients