* All experimental methods are cited from the reference, please refer to the original source for details. We do not guarantee the accuracy of the content in the reference.
Stage #1: With sodium hydroxide In dimethyl sulfoxide at 90℃; for 2 h; Stage #2: at 20 - 65℃; for 19 h;
A mixture of imidazole (1 .36 g, 20.0 mmol) and sodium hydroxide (0.80 g, 20.0 mmol) in DMSO was heated to 90 °C for 2 h, and then cooled to room temperature. A solution of 1 -bromooctane (3.46 g, 19.0 mmol) in DMSO was added dropwise to the mixture. After stirring at room temperature for 3 h, the mixture was heated up slowly to 65 °C for 16 h with constant stirring. The solution obtained was mixed with water and the product was extracted 4 times with diethyl ether. The diethyl ether phases were combined and dried with sodium sulfate. Diethyl ether was removed under vacuum and the intermediate (9) was obtained as yellow liquid (2.89 g, 89 percent). 1 H NMR (DMSO-d6): δ 7.61 (s, 2H), 7.15 (s, 1 H), 6.87 (s, 1 H), 3.93 (t, 2H), 1 .68 (m, 2H), 1 .25 (m, 10H), 0.85 (t, 3H).
87.7%
With sodium hydroxide In dimethyl sulfoxide at 20 - 25℃; Inert atmosphere
To a flask equipped with a stirrer, Add the thermometer to the three necked flask 0 · 440 g (11.0 mmol) of NaOH, 0.714 g (10.5 mmol) of imidazole and 10 mL of dimethylsulfoxide (DMSO) were stirred under nitrogen at 20 ° C to 25 ° C to give a clear solution. To this was added dropwise 1.93 g (10.0 mmol)Bromo octane, reaction 4 ~ 6 h, the reaction into 10 mL of water extracted with chloroform 3 X 10 mL, and then washed with water chloroform layer 4 ~ 5 times, and then dried with anhydrous MgS04, filtered to get the filtrate, Removal of chloroform yielded a pale yellow liquid, 1.58 g of N-octylimidazole, in 87.7percent yield.
85%
With sodium hydroxide In tetrahydrofuran; waterReflux
General procedure: A solution of imidazole 3 (30 mmol) in THF (60 mL) was treated with NaOH (25 mL, 40percent aq) and the alkyl bromide (30 mmol), and the reaction was refluxed overnight. The solvent was evaporated and the crude reaction mixture was extracted with CH2Cl2 against water. The organic layer was washed with water, dried over MgSO4 and concentrated. The final product was distilled under vacuum (~5 mbar) to provide 4 as yellow oily liquid in 80-85percent yield.
82.3%
Stage #1: With potassium hydroxide In dimethyl sulfoxide at 20℃; for 2 h; Stage #2: for 4 h;
General procedure: A mixture of imidazole (30 mmol, 2.04 g), potassiumhydroxide (30 mmol, 1.68 g) and dimethyl sulfoxide(10 mL) was stirred for 2 h at room temperature. Afterthat, alkyl bromide (25.0 mmol of 1-bromohexane, 1-bromooctane,1-bromodecane, 1-bromododecane, 1-bromotetradecane,1-bromohexadecane, or 1-bromooctadecane)was dropped in slowly and the mixture was stirred for anadditional 4 h. Upon completion, water (30 mL) was addedto the resulting mixture followed by extraction with chloroform(5 x 30 mL). The combined organic layer wasdried over anhydrous magnesium sulfate and the filtratewas concentrated under reduced pressure. The residue wassubjected to flash chromatography with ethyl acetate aseluent to give N-alkyl imidazole. The respective yields ofN-hexyl imidazole, N-octyl imidazole, N-decyl imidazole,N-dodecyl imidazole, N-tetradecyl imidazole, N-hexadecylimidazole and N-octadecyl imidazole are 84.6, 82.3, 81.2,80.5, 80.4, 79.8 and 79.6 percent.
60%
Stage #1: With sodium hydride In tetrahydrofuran for 0.75 h; Inert atmosphere; Cooling with ice Stage #2: at 20℃; for 24 h; Inert atmosphere
Imidazole (3.41 g, 50 mmol) and NaH (1.34 g, 54 mmol) were dissolved in THF (10 mL) under N2 in an ice bath for 45 min, followed by addition of 1-bromooctane (9.65 g, 50 mmol). The solution was stirred for 24 h at room temperature and then concentrated under reduced pressure after filtration.The residue was purified by flash chromatography (SiO2; petroleum ether/ethyl acetate5 : 1 as eluent) to give 1 as alight yellow oil (5.97 g, 60 percent). δH (CDCl3, 400 MHz) 7.42 (1H, s), 7.01 (1H, s), 6.87 (1H, s), 3.89 (2H, t, J 8.0), 1.76–1.73 (2H, m), 1.31–1.25 (10H, m), 0.87 (3H, t, J 7.2). δC (CDCl3, 100 MHz) 136.2, 128.4, 118.1, 46.4, 31.2, 30.6, 28.6, 28.5,26.0, 22.1, 13.6. m/z (ESI) 181 ([M + H]+). m/z 181.1708. HRMS (ESI) Anal. Calc. for C11H21N2 ([M + H]+) 181.1705.
Reference：
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2
[ 288-32-4 ]
[ 629-04-9 ]
[ 21252-69-7 ]
Yield
Reaction Conditions
Operation in experiment
80%
With potassium carbonate In acetoneReflux
General procedure: Briefly, a mixture of imidazole (100 mmol), alkyl bromide (100 mmol) and K2CO3 (200 mmol) inacetone (200 mL) was refluxed overnight. Upon filtration and solvent removal, the remaining residuewas subjected to flash chromatography with ethyl acetate to produce >90percent yield.
Reference：
[1] Molecules, 2018, vol. 23, # 9,
3
[ 288-32-4 ]
[ 629-27-6 ]
[ 21252-69-7 ]
Reference：
[1] Russian Journal of Applied Chemistry, 1996, vol. 69, # 12, p. 1841 - 1848
[2] Journal of the American Chemical Society, 2008, vol. 130, # 38, p. 12590 - 12591
[3] Journal of Materials Chemistry A, 2013, vol. 1, # 22, p. 6572 - 6578
[4] RSC Advances, 2018, vol. 8, # 26, p. 14623 - 14632
4
[ 111-86-4 ]
[ 21252-69-7 ]
Reference：
[1] Patent: US4450277, 1984, A,
5
[ 288-32-4 ]
[ 111-85-3 ]
[ 21252-69-7 ]
Reference：
[1] European Journal of Medicinal Chemistry, 1990, vol. 25, # 5, p. 449 - 454
6
[ 927690-63-9 ]
[ 21252-69-7 ]
Reference：
[1] Journal of Surfactants and Detergents, 2014, vol. 17, # 3, p. 383 - 390
7
[ 64777-25-9 ]
[ 21252-69-7 ]
Reference：
[1] Journal of Organic Chemistry, 1957, vol. 22, p. 1323,1325
A mixture of imidazole (1 .36 g, 20.0 mmol) and sodium hydroxide (0.80 g, 20.0 mmol) in DMSO was heated to 90 C for 2 h, and then cooled to room temperature. A solution of 1 -bromooctane (3.46 g, 19.0 mmol) in DMSO was added dropwise to the mixture. After stirring at room temperature for 3 h, the mixture was heated up slowly to 65 C for 16 h with constant stirring. The solution obtained was mixed with water and the product was extracted 4 times with diethyl ether. The diethyl ether phases were combined and dried with sodium sulfate. Diethyl ether was removed under vacuum and the intermediate (9) was obtained as yellow liquid (2.89 g, 89 %). 1 H NMR (DMSO-d6): delta 7.61 (s, 2H), 7.15 (s, 1 H), 6.87 (s, 1 H), 3.93 (t, 2H), 1 .68 (m, 2H), 1 .25 (m, 10H), 0.85 (t, 3H).
87.7%
With sodium hydroxide; In dimethyl sulfoxide; at 20 - 25℃;Inert atmosphere;
To a flask equipped with a stirrer, Add the thermometer to the three necked flask 0 · 440 g (11.0 mmol) of NaOH, 0.714 g (10.5 mmol) of imidazole and 10 mL of dimethylsulfoxide (DMSO) were stirred under nitrogen at 20 C to 25 C to give a clear solution. To this was added dropwise 1.93 g (10.0 mmol)Bromo octane, reaction 4 ~ 6 h, the reaction into 10 mL of water extracted with chloroform 3 X 10 mL, and then washed with water chloroform layer 4 ~ 5 times, and then dried with anhydrous MgS04, filtered to get the filtrate, Removal of chloroform yielded a pale yellow liquid, 1.58 g of N-octylimidazole, in 87.7% yield.
85%
With sodium hydroxide; In tetrahydrofuran; water;Reflux;
General procedure: A solution of imidazole 3 (30 mmol) in THF (60 mL) was treated with NaOH (25 mL, 40% aq) and the alkyl bromide (30 mmol), and the reaction was refluxed overnight. The solvent was evaporated and the crude reaction mixture was extracted with CH2Cl2 against water. The organic layer was washed with water, dried over MgSO4 and concentrated. The final product was distilled under vacuum (~5 mbar) to provide 4 as yellow oily liquid in 80-85% yield.
82.3%
General procedure: A mixture of imidazole (30 mmol, 2.04 g), potassiumhydroxide (30 mmol, 1.68 g) and dimethyl sulfoxide(10 mL) was stirred for 2 h at room temperature. Afterthat, alkyl bromide (25.0 mmol of 1-bromohexane, 1-bromooctane,1-bromodecane, 1-bromododecane, 1-bromotetradecane,1-bromohexadecane, or 1-bromooctadecane)was dropped in slowly and the mixture was stirred for anadditional 4 h. Upon completion, water (30 mL) was addedto the resulting mixture followed by extraction with chloroform(5 x 30 mL). The combined organic layer wasdried over anhydrous magnesium sulfate and the filtratewas concentrated under reduced pressure. The residue wassubjected to flash chromatography with ethyl acetate aseluent to give N-alkyl imidazole. The respective yields ofN-hexyl imidazole, N-octyl imidazole, N-decyl imidazole,N-dodecyl imidazole, N-tetradecyl imidazole, N-hexadecylimidazole and N-octadecyl imidazole are 84.6, 82.3, 81.2,80.5, 80.4, 79.8 and 79.6 %.
60%
Imidazole (3.41 g, 50 mmol) and NaH (1.34 g, 54 mmol) were dissolved in THF (10 mL) under N2 in an ice bath for 45 min, followed by addition of 1-bromooctane (9.65 g, 50 mmol). The solution was stirred for 24 h at room temperature and then concentrated under reduced pressure after filtration.The residue was purified by flash chromatography (SiO2; petroleum ether/ethyl acetate5 : 1 as eluent) to give 1 as alight yellow oil (5.97 g, 60 %). deltaH (CDCl3, 400 MHz) 7.42 (1H, s), 7.01 (1H, s), 6.87 (1H, s), 3.89 (2H, t, J 8.0), 1.76-1.73 (2H, m), 1.31-1.25 (10H, m), 0.87 (3H, t, J 7.2). deltaC (CDCl3, 100 MHz) 136.2, 128.4, 118.1, 46.4, 31.2, 30.6, 28.6, 28.5,26.0, 22.1, 13.6. m/z (ESI) 181 ([M + H]+). m/z 181.1708. HRMS (ESI) Anal. Calc. for C11H21N2 ([M + H]+) 181.1705.
General procedure: These compoundswere obtained fromthe reaction of the sodium salt of imidazole and 1-bromoalkanes, as follows: to a 3-necked round-bottom flask, provided with a reflux condenser, dropping funnel, and inlet for dry nitrogen was added a solution of imidazole (7.49 g; 0.11 mol) in dry ethanol (25 mL). Small pieces of sodium (2.53 g, 0.11 mol), were slowly introduced, the mixture was vigorously stirred until the metal has dissolved and then heated under reflux for 2 h. The mixture was cooled to room temperature; the appropriate 1-bromoalkane (0.10 mol; 16.50 g, 17.91 g, 19.31 g, 22.12 g for R ¼ C6; C7; C8 and C10, respectively)was added slowly (ca. 30 min); then the mixture was refluxed for 2 h. The mixture was cooled to room temperature, the precipitated NaBr was filtered off; the ethanol evaporated, the residual oilwas washed with water, and then dried with anhydrous MgSO4. The N-(1-alkyl)imidazoles were purified by fractional distillation (yields before distillation ca. 98%); their purity was confirmed with 1H NMR spectroscopy (results not shown).
General procedure: N-Hexadecylbromide (11.35 g, 37.2 mmol) was dissolved in dimethylformamide (DMF, 50 mL) and then added to a solution of the sodium salt of imidazole, which was formed by the reaction of imidazole (5.0 g, 74 mmol) with sodium hydride (2.66 g, 111 mmol) in DMF (50 mL). The mixture was heated at 60 C for 6 h, cooled, and diluted with water. After extraction with ethyl acetate (EtOAc), the extract was washed with brine and water, and then dried with sodium sulfate. The solvent was separated by reduced pressure distillation and N-alkylimidazole was obtained as a pale yellow oily product.
With potassium hydroxide; In acetonitrile; for 4h;Reflux;
General procedure: N-Butylimidazole and N-octylimidazole were synthesized fol-lowing the procedure of literature [44]: To a round-bottomedflask, imidazole (6.0 g, 88 mmol), 1-bromobutane/1-bromooctane(90 mmol), acetonitrile (50 mL) and potassium hydroxide (9.9 g,177 mmol), were added in sequence. The reaction mixture wasrefluxed for 4 h and then cooled down to room temperature. Afterevaporating the solvent, the residue was purified by a flash col-umn chromatography utilizing ethyl acetate/methanol (v/v = 25:1)as eluent. The pure product of 1-butylimidazole/1-octylimidazolewas isolated as a pale yellow oil (?83%). N-Octylimidazole:1H NMR: (CDCl3): (ppm) = 0.87 (t, J = 6.5 Hz,3H, CH3), 1.28 (br, 10H, CH2), 1.77 (br, 2H, CH2), 3.92 (t, J = 7.2 Hz,2H, CH2), 6.90 (s, 1H, ImH), 7.04 (s, 1H, ImH), 7.45 (s, 1H, ImH).13CNMR (CDCl3): (ppm) = 13.9, 22.5, 26.4, 28.9, 29.0, 31.0, 31.6, 46.9,118.7, 129.2, 136.9.
With sodium hydroxide; In acetone; at 20℃; for 12h;
N-alkylimidazoles were synthesized using a previously reported method with minor modification. Typically, to a solution of imidazole (1 mol equiv.) and sodium hydroxide (1 mol equiv.) in acetone (50 mE) was added 1 -bromoalkane (0.8 mol equiv.). After stirring at room temperature for 12 h, a Nal3r precipitate was filtered and acetone removed under reduced pressure. A residual oily mass was re-dissolved in dichloromethane and extracted three times with water. Finally, an organic phase was dried on anhydrous sodium sulfate and dicholoromethane was removed under reduced pressure to produce brown oil.
In einen 2 I Schlenkkolben werden 830,5 g (5 mol) 1-Octylimidazol vorgelegt und 630,5g (5 mol) Dimethylsulfat portionsweise zugegeben. Der Ansatz wird danach 15 Minuten nachgeruehrt. Der Kolbeninhalt wird danach in ein 5I Becherglas ueberfuehrt und zu einer Mischung von 548,0g (5 mol) Natriumtetrafluoroborat in 2 Liter Wasser gegeben. Sofort bildetsich das Produkt als zweite, fluessige Phase. . Nach einer Phasentrennung wird die waessrige Phase noch einmal mit 1 Liter CH2Cl2extrahiert, und das organische Extrakt von Methylenchlorid befreit. Beide Produktfraktionen werden vereinigt und ueber Nacht bei 60°C am HV getrocknet. Man erhaelt 1-Octyl-3-methylimidazoliumtetrafluoroborat in 94 percentiger Ausbeute. Zum qualitativen Nachweis auf Chloridreste, werden ca. 1 ml des Produktes mit ca. 5 ml Wasser versetzt und mit 2 Tropfen konzentrierter Salpetersaeure angesaeuert. Zu dieser Loesung werden dann ca. 3-4 Tropfen Silbernitrat gegeben um etwaig vorhandenes Chlorid als Silberchlorid auszufaellen. Das Ausbleiben eines Silberchlorid-Niederschlags spricht fuer die komplette Abwesenheit von Chloridresten. [26.1] 1H-NMR (300 MHz, CDCl3):delta=9.3 ppm (s,1H,Ha); delta=7.26 ppm (d,1H,Hc); delta=7.24 ppm (d,1H,Hd); delta=4.1 ppm (t,2H,He); delta=3.9 ppm (s,2H,Hb); delta=1.6 ppm (m,2H,Hf); delta=1.2 ppm (m,10H,Hg,h,i,j,k); delta=0.8 ppm (t,3H,HI).13C-NMR (75 MHz, CDCl3):delta=137 ppm (C1); delta=124-122 ppm (C3,C4); delta=48 ppm (C5); delta=35 ppm (C2); delta=29-24 ppm (C6-C10); delta=20 ppm (C11); delta=13 ppm (C12).19F-NMR (281 MHz, CDCl3):delta= -151,3 ppm (d, 1J(BF)= 22 Hz)
EXAMPLE 3 Preparation of 1-octylimidazole 64.6 parts of n-octylamine and 34 parts of 25percent strength aqueous ammonia aredissolved in 186 parts of propanol and are introduced dropwise over 30 minutes, simultaneously with a mixture of 72.5 parts of 40percent strength aqueous glyoxal solution and 37.5 parts of 40percent strength aqueous formaldehyde solution, into a stirred flask. The temperature is kept at 65° C. After all has been introduced, stirring is continued for 20 minutes at 65° C., and the mixture is then worked up by distillation. 64.2 parts of 1-octylimidazole (boiling point 110° C./1 mm Hg) are obtained, corresponding to a yield of 71.3percent of theory.
at 80℃; for 1h;Inert atmosphere; Microwave irradiation;
These ILs were obtained by the reaction of the appropriate N-(1-alkyl)imidazole with allyl chloride (3-chloro-1-propene), under microwave (MW) irradiation as follows, for 1-allyl-3-(1-hexyl) imidazolium chloride, AlHxImCl; 1-allyl-3-(1-heptyl)imidazolium chloride, AlHpImCl; 1-allyl-3-(1-octyl)imidazolium chloride AlOcImCl; 1-allyl-3-(1-decyl)imidazoliumchloride, AlDcImCl. N-(1-alkyl) imidazole (0.22 mol; 33.49 g, 36.58 g, 39.66 g, 45.8 g for R ¼ C6; C7; C8 and C10) and 3-chloro-1-propene (0.25 mol; 19.13 g) were mixed in a glass reactor, provided with a reflux condenser and inlet for dry nitrogen; the reactor was introduced in the cavity of the MWapparatus (Discover model DU-8316; CEM; Matthews) and irradiated under vigorous stirring for 1 h; 20W, 80 C. The product was dissolved in ethyl acetate (100 mL); the solution placed in a freezer (phase separation of the IL); the upper layer discarded; this process was repeated thrice. After removal of ethyl acetate, the IL was dried at 110 C,1 mmHg for 12 h. The yields were 98 1percent (light yellow viscous liquid in all cases). 2.2.3.3 1-Allyl-3-(1-octyl)imidazolium chloride Light-yellow, viscous liquid. 1H NMR for C14H25N2Cl: 0.88 (3H, t, J = 7.0, H13), 1.20-1.39 (10H, m, H12), 1.88-1.96 (2H, m, H11), 4.34 (2H, t, J = 7.4, H10), 5.07 (2H, d, J = 6.5, H6), 5.46 (1H, m, H9), 5.48 (1H, m, H8), 6.03 (1H, m, H7) 7.26 (2H, s, H4 & H5), 10.93 (1H, s, H2). Calcd. for C14H25N2ClO4: C, 52.4percent; H, 7.9percent; N, 8.7percent. Found: C, 52.5percent; H, 7.9percent; N, 8.8percent.
A solution of <strong>[21252-69-7]1-octylimidazole</strong> (3.97 g, 22 mmol) and 1,2-dibromoethane (2.07 g, 11 mmol) in MeCN (20 mL) was refluxedfor 3 days. After cooling to room temperature, the precipitate wasfiltered and washed with THF three times. Drying in a vacuum ovengave colorless crystalline bromide salt (4.51 g, 75%). A solution ofthe bromide salt and NaI (4 equiv.) in deionized water was stirredfor 24 h at ambient temperature. The precipitate was filtered anddrying in a vacuum oven gave a colorless crystalline solid BII-8(5.07 g, 96% from the bromide salt). MP 210-211 C. 1H NMR(500 MHz, CDCl3, 23 C): delta 0.89 (t, J 8, 6H), 1.29-1.36 (m, 20H),1.95 (m, 4H), 4.19 (t, J 8, 4H), 5.29 (s, 4H), 7.27 (t, J 1.5, 2H), 8.84(t, J 1.5, 2H), 10.3 (s, 2H). 13C NMR (125 MHz, CDCl3, 23 C): delta 14,22, 26, 28.8, 29.1, 30, 32, 48, 51, 122, 124, 137.
Synthesis of 1-octyl-3(propyl-3-sulfonyl) imidazolium 1 equivalent of 1 -octyl-imidazole was reacted with 1 equivalent of propanesultone at reflux temperature in 10percent toluene as solvent. After 10 hours, the mixture was cooled down at room temperature and then filtrated. The cake was washed with 3 portions of toluene before drying under high vacuum at 60°C.
In acetonitrile; at 80℃; for 24h;Inert atmosphere;
General procedure: 1,2-Dimethyl imidazole (9.61 g; 0.10 mol) and trimethylphosphate (14.01 g; 0.10 mol) were mixed at room temperature under argon and vigorous stirring, then heated to 80°C and stirred at this temperature for 1h. Acetonitrile (20 mL) was added and the mixture was stirred at 80°C for 23h. The mixture was left at room temperature, the precipitate was separated,washed twice with acetonitrile and dried under vacuum (2 Torr) for 4 h at 80°C.
General procedure: Dicationic imidazolium ionic liquids were prepared by refluxing-N-hexadecylimidazole (5.85 g, 20 mmol) and 1,4-dibromobutane (2.16 g, 10 mmol) in isopropanol (50 mL) at 80 °C for 24 h. Then, the products were washed with diethyl ether four times under vacuum.
In acetonitrile; at 100℃; for 24h;Sealed tube; Inert atmosphere;
General procedure: To a screw capped tube flask,chloroalkylated quaternary ammonium salt 2 and 5 equivalents of alkyl imidazole 3 were added with acetonitrile (5 ml). The sealed flask was heated at 100 for 24h. After the solvent was removed by evaporation, the residue was dissolved in a small amount of dichloromethane. The solution was poured into ethyl acetate, anoily imidazolium salt was separated from an organic phase. In case of 4ao, it was recrystallized in ethylacetate. Salt 4 was also moisture-sensitive as 2.
In acetonitrile; at 100℃; for 24h;Sealed tube; Inert atmosphere;
General procedure: To a screw capped tube flask,chloroalkylated quaternary ammonium salt 2 and 5 equivalents of alkyl imidazole 3 were added with acetonitrile (5 ml). The sealed flask was heated at 100 for 24h. After the solvent was removed by evaporation, the residue was dissolved in a small amount of dichloromethane. The solution was poured into ethyl acetate, anoily imidazolium salt was separated from an organic phase. In case of 4ao, it was recrystallized in ethylacetate. Salt 4 was also moisture-sensitive as 2.
1-octyl-3-[2-(2,3,4,6-tetra-O-acetyl-β-D-glucopyranosyloxy)ethyl]imidazolium bromide[ No CAS ]
Yield
Reaction Conditions
Operation in experiment
95%
In 5,5-dimethyl-1,3-cyclohexadiene; at 125℃; for 1h;
General procedure: A solution of 2-bromoethyl glucoside 2 (1.1 mmol) and the alkylated imidazole 4 (3.3 mmol) in xylene (2 mL) was heated to 125 °C for 1 h. The solvent was evaporated and the crude product was taken up in MeCN (10 mL) and extracted 4 times with hexane (60 mL) to remove remaining imidazole 4. The acetonitrile phase was concentrated under reducing pressure to provide the desired product 5 as a pale yellow syrup in ~95percent yield.
3-(6-bromohexyl)-1-octylimidazolium bromide[ No CAS ]
Yield
Reaction Conditions
Operation in experiment
85%
In acetonitrile; for 24h;Reflux; Inert atmosphere;
1,6-Dibromohexane (10.00 g, 42 mmol) was dissolved in anhydrous acetonitrile (10 mL) and introduced into a three-neck round-bottom flask. After the solution was heated gently to reflux, a solution of 1 (0.50 g, 2.80 mmol) in anhydrous acetonitrile (5 mL) was added dropwise under N2 atmosphere. The reaction mixture was stirred for 24 h at reflux and then cooled to room temperature. The solvent was removed to give a residue, which was purified by washing with anhydrous diethyl ether (35 mL), and concentrated under reduced pressure. The residue was dried under vacuum to afford 2 as a puce oil (1.01 g,85 percent). deltaH (CDCl3, 400 MHz) 10.32 (1H, s), 7.62 (1H, s), 7.50 (1H, s), 4.40 (2H, t, J 7.2), 4.34 (2H, t, J 7.6), 3.43?3.40 (4H, m), 2.03?1.84 (6H, m), 1.51?1.23 (12H, m), 0.87 (3H, t, J 6.8). deltaC (CDCl3, 100 MHz) 136.3, 122.1, 121.8, 49.9, 49.6, 33.7, 32.3,32.1, 31.5, 30.1, 30.0, 28.9, 27.2, 26.1, 25.1, 22.4, 14.0. m/z (ESI) 345 ([M]+). m/z 345.1733. HRMS (ESI) Anal. Calc. for C17H32BrN2 ([M]+) 345.1728.
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