Bicyclic Thiadiazoles I: 2-(2-Thienyl)-5-phenylthiazolo[2,3-b]-1,3,4-thiadiazole

Carbon-13 nuclear magnetic resonance studies of heterocycles bearing carbon-sulfur and carbon-selenium bonds: 1,3,4-thiadiazole, 1,3,4-selenadiazole, and tetrazole derivatives

“…)-1,3,4-3.H-thiadiazoline-2-selone (5) [95% from 4-(p-tolyl)-3-thiosemicarbazide4]: pale pink felted needles; mp 156-157 °C dec; UV Xmax (95% ethanol) 239 (e 13 600), 296 (5500), 343 nm (16 800); NMR SMe4si (Me2SO-d6) 2.28 (s, 3), 7.17 (m, 2), 7.32 (m, 2), 10.18 (s, 1), 14.25 (hr s, 1).…”

“…The solid which had separated was collected, dissolved in dichloromethane, and reprecipitated with ether. The pure tetrazolium salt had: mp 156.5-157.5 °C (9.9 g); IR rmax 1598, 1500, 1450, 1424, 1055 (vs, BF4"), 776, 695 cm"1; UV Xmax (CH2C12) 271 (sh) nm (e 4000); NMR SMe4s¡ (Me2SO-d6) 1.69 (t, J = 7.5 Hz, 3), 2.88 (s, 3), 5.05 (q, J = 7.5 Hz, 2), 6.80 (s, 5 the lower melting point, this fraction was identical ( NMR) with the analytical sample. Prolonged drying in vacuo reduced the total weight of product from 24.3 to 23.1 g (100%).…”