7-Bromo-3-methyl-[1,2,3]triazolo[1,5-a]pyridine 1 at 1.7 atm and 100ºC decompose to form a pyridylcarbene intermediate by nitrogen expulsion. The carbene stabilization give 2-bromo-6vinylpyridine 2, 1-(6-bromopyridin-2-yl)ethanol 3, 1-(6-Bromopyridin-2-yl)ethanone 4, 2bromo-6-[2-(6-bromopyridin-2-yl)-2-methyl-trans-cyclopropyl]pyridine 5, and 2-bromo-6-[2-(6bromopyridin-2-yl)-2-methyl-cis-cyclopropyl]pyridine 6. ARKAT USA, Inc. made using a VG Autospec Trio 1000 (Fisons). Chromatography was

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... ormed on a Chromatotron, using 2 cm plates of silica Merck Pf254. Thermal decomposition under pressure of 7-bromo-3-methyl-[1,2,3]triazolo[1,5-a]pyridine A solution of 7-bromo-3-methyl-[1,2,3]triazolo[1,5-a]pyridine 1 (300mg, 1.42mmol) in dry acetonitrile (75 mL) was poured in a test tube into a steel reactor that was hermetically closed. The reactor was heated at 100ºC during 5 days. Then, it was cooled to reach room temperature. An intractable solid was formed that was filtered. The filtrate was dried and a complex mixture was obtained (190mg). The mixture was purified by chromatography on a chromatrotron using ethyl acetate/hexane with an increasing proportion of ethyl acetate as eluent. The following compounds, by elution order, were isolated and characterized. 2-Bromo-6-vinylpyridine (2). Colourless oil. Yield 1%. HRMS found M + 184.9660 / 182.9671; C 7 H 6 BrN requires 184.9663 / 182.9683. 1 H NMR δ 7.43 (dd, J 1 =J 2 =7.7Hz, 1H), 7.27 (d, J=7.70Hz, 1H), 7.20 (d, J=7.7Hz, 1H), 6.66 (dd, J 1 =17.3Hz, J 2 =10.5Hz, 1H), 6.17 (dd, J 1 =17.3Hz, J 2 =1.1Hz, 1H), 5.46 (dd, J 1 =10.5Hz, J 2 =1.1Hz, 1H). 13 C NMR δ 157.41 (C), 142.39 (C), 139.12 (CH), 135.78 (CH), 127.04 (CH), 120.39 (CH), 120.28 (CH 2 ). MS m/z 185, 183, 159, 157, 104, 77, 57, 51. 2-Bromo-6-[2-(6-bromopyridin-2-yl)-2-methyl-trans-cyclopropyl]pyridine (5). White solid. Mp 105ºC. Yield 8%. (EI) HRMS found M + 369.9318 / 367.9346 / 365.9360; C 14 H 12 Br 2 N 2 requires 369.9326 / 367.9347 / 365.9367. 1 H NMR δ 7.37 (dd, J 1 =J 2 =7.7Hz, 1H), 7.35 (dd, 67 (CH), 138.45 (CH), 125.54 (CH), 125.06 (CH), 123.56 (CH), 118.91 (CH), 35.56 (CH), 29.72 (C), 22.78 (CH 2 ), 15.61 (CH 3 ). MS m/z 369, 368, 367, 288, 287, 275, 274, 273. 1-(6-Bromopyridin-2-yl)-ethanone (4). 11 Colourless oil. Yield 4%. HRMS found M + 200.9605 / 198.9621; C 7 H 6 BrNO requires 200.9612 / 198.9633. 1 H NMR δ 7.92 (d, J=6.8Hz, 1H), 7.63 (m, 2H), 2.64 (s, 3H). 13 C NMR δ 190.0 (CO), 154.7 (C), 141.7 (C), 139.5 (CH), 132.9 (CH), 26.2 (CH 3 ). MS m/z 201, 199, 173, 172, 159, 78, 61, 50. 2-Bromo-6-[2-(6-bromopyridin-2-yl)-2-methyl-cis-cyclopropyl]pyridine (6). White solid. Mp 72-73ºC. Yield 15%. (FAB) HRMS found (M+1) + 370.9425 / 368.9441 / 366.9451; C 14 H 13 Br 2 N 2 requires 370.9405 / 368.9426 / 366.9445. 1 H NMR δ 7.26 (dd, J 1 =J 2 =7.7Hz, 1H), 7.17 (dd, J 1 =J 2 =7.7Hz, 1H), 7.08 (d, J=7.7Hz, 2H), 6.99 (dd, J 1 =7.9Hz, J 2 =0.75Hz, 1H), 6.85 (dd,