SUPPORTING INFORMATION Introduction 1 DSC scan 5-bromo-2-aminopyridine..3 DSC scan 5-bromo-2-nitropyridine.....4 Oxidant mixture. Adiabatic test stability, glass cell and Hastelloy C22 test cell 5 Hastelloy C22 SHR graph..6 Reaction calorimetry for reaction quench..7 TMR calculation comparison..8 azo-oxy impurty synthetic procedure..9 1 H NMR azo-oxy impurity........10 13 C NMR azo-oxy impurity...........11 1 H NMR 5-bromo-2-aminopyridine........12 13 C NMR 5-bromo-2-aminopyridine.......13 1 H NMR 5-bromo-2-nitropyridine......14 13 C NMR 5-bromo-2-nitropyridine........15 1
Introduction DSC thermograms were recorded using gold plated, high pressure crucibles provided by TUV-SUD Schweiz AG on a Perkin Elmer DSC 8000 instrument. Proton and carbon NMR were recorded using a Varian Mercury 300 MHz instrument, chemical shift reported in ppm against the residual solvent peak. Adiabatic calorimetry experiments were conducted using a PhiTEC 1 instrument from HEL Ltd., UK utilized in Heat-Wait-Search mode with a sensitivity for exothermic detection of 0.02 C/min. Glass test cell were provided by HEL Ltd. and Hastelloy C22 test cells were provided by Thermal Hazard Technology, UK. 2
DSC scan 5-bromo-2-aminopyridine High pressure, gold plated crucible. 30-400 C, 5 C/min scan rate 3
DSC scan 5-bromo-2-nitropyridine High pressure, gold plated crucible. 30-400 C, 5 C/min scan rate 4
Oxidant mixture. Adiabatic test stability, glass cell Glass test cell and Hastelloy test cell. P,T vs. time 5
Hastelloy test cell. SHR ( C/min) vs. temperature 6
Reaction calorimetry of reaction mixture quench 7
Glass test cell and Hastelloy test cell. TMR calculation 8
1,2-bis((5-bromopyridine-2-yl)diazene oxide Dimethyl-N-(5-bromo-2-aminopyridyl)sulfililimide In 4-neck round bottomed flask DMSO (2.86 g, 36.6 mmol) was added together with dichloromethane (125 ml) under argon atmosphere. The solution was cooled at -78 C whereupon triflic anhydride (9.35 g, 5.6 ml, 32.5 mmol) was slowly added (40 min) while maintaining the temperature below -70 C. After 10 minutes at -78 C a suspension formed and a solution of 5-bromo-2-aminopyridine (5 g, 28.3 mmol) in DMSO (25 ml) was added over 5 min while keeping the temperature below -70 C. The mixture was stirred for 2h at -78 C and 1h at -55 C. The mixture was brought to -20 C whereupon NaOH 2M (30 ml) was added and the mixture stirred for 10 min (ph=7). Water (850 ml) and dichloromethane (70 ml) were added at room temperature, the mixture stirred for 5 minutes and the phases separated. The aqueous phase was extracted twice with dichloromethane. The combined organic layers were dried over Na 2 SO 4, filtered and the solvent evaporated at reduced pressure yielding 5.77 g of a yellow oil. 1,2-bis((5-bromopyridine-2-yl)diazene oxide In a 3 neck round bottomed flask, under argon atmosphere, Dimethyl-N-(5-bromo-2- aminpyridyl)sulfililimide (1.32 g, 5.66 mmol) was added together with dichloromethane (6.6 ml). m-chloro perbenzoic acid (1.27 g, 5.66 mmol) was added in small portions while maintaining room temperature by means of a water bath. The mixture was stirred at room temperature for 24h. A solution of Na 2 CO 3 saturated (20 ml) and dichloromethane 815 ml) were added to the mixture. The phases were separated, the organic phase washed with water (20 ml) and the water phase was back-extracted with dichloromethane (10 ml). The combined organic phase was dried over Na 2 SO 4, filtered and the solvent evaporated yielding 0.95 g (94% yield, purity 99%, ~1% starting material) as brown powder. This powder was triturated with refluxing ethyl acetate (5 ml), then cooled and the solid was isolated by filtration. The solid was dried under vacuum delivering 610 mg (60% yield, purity > 99.5%) as a light brown powder. 1 H NMR (DMSO): δ in ppm (integral, multiplicity, Hz) 8.83 (1H, dd, 0.56, 2.38) 8.82 (1H, dd, 0.64, 2.49) 8.48 (1H, dd, 2.40, 8.65) 8.28 (1H, dd, 0.60, 8.64) 8.02 (1H, dd, 0.67,8.69) 13 C NMR (DMSO): δ in ppm (type of carbon) 150.33 (C-H), 149.48 (C-H), 142.74 (C-H), 140.86 (C-H), 119.60 (C-H), 119.46 (C-H) LC/MS data (ESI) 358.8981 ([M+H] + ), 380.8789 ([M+Na] + ) 9
1 H NMR (DMSO): 1,2-bis(5-bromopyridine-2-yl)diazene oxide 10
13 C NMR (DMSO): 1,2-bis(5-bromopyridine-2-yl)diazene oxide 11
1 H NMR (DMSO): 5-bromo-2-aminopyridine 12
13 C NMR (DMSO): 5-bromo-2-aminopyridine 13
1 H NMR (DMSO): 5-bromo-2-nitropyridine 14
13 C NMR (DMSO): 5-bromo-2-nitropyridine 15