Was then filtered by means of ALDH1 list slow-filtering paper (e.g., Whatman Grade 50) and
Was then filtered by means of slow-filtering paper (e.g., Whatman Grade 50) and acidified to pH = two by the slow addition of hydrochloric acid (four M aqueous option) to offer a lemon yellow slurry. Following five h, the solid was collected on a filter, washed with HCl (0.1 M aqueous solution, five 20 mL) and water (50 mL), and dried in vacuo. The dry residue was heated at reflux in acetonitrile (25 mL) for 20 min. Immediately after standing at 5 for two h, the strong was collected on a filter, washed with cold acetonitrile (5 3 mL), and dried in vacuo to offer six (4.479 g, 62 ) as a lemon yellow solid [product might have contained residual acetonitrile (300 mol- , 1.5 wt.- )]; m.p. 280 (steadily turned black, decomposition). HPLC purity 95 . C40H40O7S12 (1017.47): calcd. C 47.21, H three.96, S 37.82; discovered C 46.91, H four.12, S 37.36. MS (ESI): calcd. for C40H39O7S12 [M H]- 1014.935; discovered 1014.946. IR (KBr): = 2963 (m), 2918 (m), 2860 (m), 1688 (s), 1508 (m), 1453 (m), 1431 (m), 1367 (m), 1317 (m), 1261 (m), 1223 (s), 1167 (m), 727 (w) cm-1. 1H NMR (400 MHz, [D6]DMSO): = 1.59 (s, 9 H, CH3), 1.62 (s, 9 H, CH3), 1.69 (s, 9 H, CH3), 1.72 (s, 9 H, CH3), two.07 (s, 0.8.two H, acetonitrile), six.79 (s, 1 H, OH) ppm. 13C NMR (one hundred MHz, [D6]-DMSO): = 27.52 (CH3), 28.56 (CH3), 31.35 (CH3), 33.92 (CH3), 60.72 (SCS), 60.80 (SCS), 83.59 (COH), 122.11 (C), 133.40 (C), 138.33 (C), 139.87 (C), 140.60 (C), 140.94 (C), 167.06 (CO2H) ppm. Tris(8-carboxy-2,2,six,6-tetramethylbenzo[1,2-d;4,5-d]bis[1,3]dithiol-4-yl)methyl (five) and Quinone Methide 7 A suspension of 6 (0.375 g, 0.37 mmol) in freshly distilled TFA (4 mL) was stirred for 16 h at room temp. below argon.[24] The deep colored greenish-brown resolution was concentrated in vacuo to give a black cake. The cake was dissolved in NaOH (2 M answer, 5 mL, ten mmol), along with the resulting answer was diluted with water (10 mL) to afford a reddish-brown option.[25] The addition of brine (10 mL) resulted within the formation of an abundant quantity of a fine precipitate. The mixture was left below argon for 4 h then filtered by way of slow-filtering paper. The deep green clear filtrate was acidified to pH = three by the addition of HCl (2 M resolution) to offer 5 (0.206 g, 56 ), which was isolated as reported above. The solid material collected around the filter and was washed with waterbrine (1:1 vv, three 5 mL). The strong was then dissolved in acidified methanol [concentrated HCl (25 ) in methanol (50 mL)]. The resulting deep purple option was concentrated in vacuo, plus the crude product was purified by IL-17 drug column chromatography on silica gel (dichloromethanemethanol, from 20:1 to three:1 vv) to afford quinoide 7 (0.078 g, 22 ) as a reddish-black powder; m.p. 280 (decomposition). Data for 7: MS (ESI): calcd. for C39H37O5S12 [M H]- 968.929; discovered 968.935. IR (KBr): = 2957 (m), 2920 (s), 2851 (m), 1686 (m), 1659 (m), 1603 (s), 1585 (s), 1495 (m), 1452 (s), 1385 (s), 1366 (s), 1231 (s), 1150 (s), 1105 (m), 733 (m) cm-1. UVVis (methanol): max (, Lmol-1cm-1) = 276 (38100), 369 (11700), 477 (9600), 529 (10800) nm. 1H NMR (400 MHz, [D6]DMSO): = 1.57 (s, 6 H, CH3), 1.63 (s, six H, CH3), 1.69 (s, 6 H, CH3), 1.71 (s, 6 H, CH3), 1.72 (s, six H, CH3), 1.76 (s, 6 H, CH3) ppm. 1H NMR (600 MHz, CD3OD): = 1.64 (s, 6 H, CH3), 1.72 (s, 6 H, CH3), 1.74 (s, 6 H, CH3), 1.76 (s, six H, CH3), 1.82 (s, six H, CH3), 1.85 (s, 6 H, CH3) ppm. 13C NMR (100 MHz, [D6]DMSO): = 29.95 (CH3), 28.27 (CH3), 30.45 (CH3), 31.18 (CH3), 33.35 (CH3), 34.52 (CH3), 60.97 (SCS), 61.67 (SCS), 62.63 (SCS), 127.30 (C), 12.