t-BuOLi promoted regioselective N-thiolation of indoles with N-arylthio phthalimide.

The selective N-thiolation of indole substrates poses a challenge due to their diminished nucleophilicity at nitrogen. Herein, we present a novel method for the thiolation of the NH group in indole derivatives by using N-arylthio phthalimide as the sulfur source, t-BuOLi as the base and MeCN as the solvent. The process was successfully conducted under transition metal catalyst-free and room temperature conditions with a high product yield and a short reaction time. The developed protocol exhibited excellent regioselectivity and broad substrate tolerance in the preparation of N-thioindoles with diverse functional groups.

Gout of feet and ankles in different stages: The potentiality of a new semiquantitative DECT scoring system in monitoring urate deposition.

The purpose of this study was to investigate the diagnostic performance of a novel semi-quantitative dual-energy computed tomography (DECT) scoring system in monitoring urate deposition. This study included 287 patients with gout. All patients underwent ankle/foot DECT scans. DECT scores at different stages were compared and their diagnostic efficacies evaluated. Associations between DECT scores and clinical variables were evaluated. Gouts with positive DECT results in early, middle, and late stages were 78.5 %, 81.4 %, and 95.8 %, respectively (all P > .05). The total and ankle/midfoot DECT scores at different stages significantly increased with disease duration (all P < .05). DECT scores of 4 regions excluding the first metatarsophalangeal joint in early and middle stages were lower than those in late stage (all P < .05). DECT scores achieved excellent diagnostic performance for differentiating gout in early stage from middle and late stages (area under the curve, 0.923 and 0.949), with high sensitivity, specificity, positive predictive value, and negative predictive value (all > 85 %). Total DECT score was highly positively correlated with the volume of urate crystals (R = 0.873, P < .001). Disease duration, serum uric acid level, bone erosion, and Achilles tendon involvement significantly affected total DECT scores (all P < .01). In conclusion, longer disease duration, higher serum uric acid levels, bone erosion, and Achilles tendon involvement were closely associated with total DECT scores. DECT scoring system may be an invaluable tool for gout diagnosis owing to its high detection efficacy and a surrogate method to evaluate the amount of urate crystals and erosion of surrounding tissues.