2-Isobutyl-3-methylpyrazine

2-Isobutyl-3-methylpyrazine has extremely powerful herbaceous green earthy notes. Diluted water solutions exhibit a characteristic odor of green bell peppers LiquidSynthesis: By condensation of ethylenediamine with 5-methyl- 2,3-hexanedione.

colourless to slightly yellow liquid with a green, earthy, celery odour

General procedure: Py-GC/MS analysis used in this study has a Pyroprobe 5250T (CDS, Analytical Inc., ) connected directly to a GC/MS (Agilent, 7890A/5975C). About 0.20 mg of each sample was centered in a 25-mm quartz tube and pyrolyzed isothermally at the designed temperatures for 10 s. Thepyrolysis temperatures were set up at 300, 450, 600, 750 and 900 C, respectively. The temperature of the reactor was initially set at 50 C and heated nominally at the rate of 10 C ms-1. The pyrolysis atmospheres were both in nitrogen (0% oxygen) and in the mixture gases of oxygen (9%) and nitrogen (91%) at 300, 450, 600 C, and in nitrogen at 750 and 900 C only. The final pyrolysis vapor was directly transferred to the GC/MS and analyzed. The chromatographic separation was performed using a DB-5MS fused silica capillary column (60 m x 250 mum id x 0.25 mum df, Agilent). The injector temperature was kept at 300 C. Initial oven temperature was set at 50 C, then heated to 80 C at the rate of 6 C min-1, followed by a heating rate of 4 C min-1 to 110 C , held there for 2 min and finished at 250 C with a rate of 5 C min-1. Helium at a constant flow rate of 1 mL min-1 was used as the carrier gas, and the split ratio was 100:1. The separated compounds were analyzed by the mass spectrometer. The EI ionization energy was 70 eV, and the transfer line temperature was 300 C. Ion source temperature was 230 C, and quadrupole temperature was 150 C. The mass spectra were obtained from m/z 30 to 500, and solvent delay time was 3.9 min. The pyrolysis products were identified by comparison between the experimental mass spectrum and mass spectrum library (NIST 11) attached to the Py-GC/MS apparatus. All quantitative data were expressed by average values of the duplicate pyrolysis runs. For each product, its peak area% value obtained under different pyrolysis conditions can be compared to reveal the changing of its relative content among the detected products.General procedure: Py-GC/MS analysis used in this study has a Pyroprobe 5250T (CDS, Analytical Inc., ) connected directly to a GC/MS (Agilent, 7890A/5975C). About 0.20 mg of each sample was centered in a 25-mm quartz tube and pyrolyzed isothermally at the designed temperatures for 10 s. Thepyrolysis temperatures were set up at 300, 450, 600, 750 and 900 C, respectively. The temperature of the reactor was initially set at 50 C and heated nominally at the rate of 10 C ms-1. The pyrolysis atmospheres were both in nitrogen (0% oxygen) and in the mixture gases of oxygen (9%) and nitrogen (91%) at 300, 450, 600 C, and in nitrogen at 750 and 900 C only. The final pyrolysis vapor was directly transferred to the GC/MS and analyzed. The chromatographic separation was performed using a DB-5MS fused silica capillary column (60 m x 250 mum id x 0.25 mum df, Agilent). The injector temperature was kept at 300 C. Initial oven temperature was set at 50 C, then heated to 80 C at the rate of 6 C min-1, followed by a heating rate of 4 C min-1 to 110 C , held there for 2 min and finished at 250 C with a rate of 5 C min-1. Helium at a constant flow rate of 1 mL min-1 was used as the carrier gas, and the split ratio was 100:1. The separated compounds were analyzed by the mass spectrometer. The EI ionization energy was 70 eV, and the transfer line temperature was 300 C. Ion source temperature was 230 C, and quadrupole temperature was 150 C. The mass spectra were obtained from m/z 30 to 500, and solvent delay time was 3.9 min. The pyrolysis products were identified by comparison between the experimental mass spectrum and mass spectrum library (NIST 11) attached to the Py-GC/MS apparatus. All quantitative data were expressed by average values of the duplicate pyrolysis runs. For each product, its peak area% value obtained under different pyrolysis conditions can be compared to reveal the changing of its relative content among the detected products.General procedure: Py-GC/MS analysis used in this study has a Pyroprobe 5250T (CDS, Analytical Inc., ) connected directly to a GC/MS (Agilent, 7890A/5975C). About 0.20 mg of each sample was centered in a 25-mm quartz tube and pyrolyzed isothermally at the designed temperatures for 10 s. Thepyrolysis temperatures were set up at 300, 450, 600, 750 and 900 C, respectively. The temperature of the reactor was initially set at 50 C and heated nominally at the rate of 10 C ms-1. The pyrolysis atmospheres were both in nitrogen (0% oxygen) and in the mixture gases of oxygen (9%) and nitrogen (91%) at 300, 450, 600 C, and in nitrogen at 750 and 900 C only. The final pyrolysis vapor was directly transferred to the GC/MS and analyzed. The chromatographic separation was performed using a DB-5MS fused silica capillary column (60 m x 250 mum id x 0.25 mum df, Agilent). The injector temperature was kept at 300 C. Initial oven temperature was set at 50 C, then heated to 80 C at the rate of 6 C min-1, followed by a heating rate of 4 C min-1 to 110 C , held there for 2 min and finished at 250 C with a rate of 5 C min-1. Helium at a constant flow rate of 1 mL min-1 was used as the carrier gas, and the split ratio was 100:1. The separated compounds were analyzed by the mass spectrometer. The EI ionization energy was 70 eV, and the transfer line temperature was 300 C. Ion source temperature was 230 C, and quadrupole temperature was 150 C. The mass spectra were obtained from m/z 30 to 500, and solvent delay time was 3.9 min. The pyrolysis products were identified by comparison between the experimental mass spectrum and mass spectrum library (NIST 11) attached to the Py-GC/MS apparatus. All quantitative data were expressed by average values of the duplicate pyrolysis runs. For each product, its peak area% value obtained under different pyrolysis conditions can be compared to reveal the changing of its relative content among the detected products.General procedure: Py-GC/MS analysis used in this study has a Pyroprobe 5250T (CDS, Analytical Inc., ) connected directly to a GC/MS (Agilent, 7890A/5975C). About 0.20 mg of each sample was centered in a 25-mm quartz tube and pyrolyzed isothermally at the designed temperatures for 10 s. Thepyrolysis temperatures were set up at 300, 450, 600, 750 and 900 C, respectively. The temperature of the reactor was initially set at 50 C and heated nominally at the rate of 10 C ms-1. The pyrolysis atmospheres were both in nitrogen (0% oxygen) and in the mixture gases of oxygen (9%) and nitrogen (91%) at 300, 450, 600 C, and in nitrogen at 750 and 900 C only. The final pyrolysis vapor was directly transferred to the GC/MS and analyzed. The chromatographic separation was performed using a DB-5MS fused silica capillary column (60 m x 250 mum id x 0.25 mum df, Agilent). The injector temperature was kept at 300 C. Initial oven temperature was set at 50 C, then heated to 80 C at the rate of 6 C min-1, followed by a heating rate of 4 C min-1 to 110 C , held there for 2 min and finished at 250 C with a rate of 5 C min-1. Helium at a constant flow rate of 1 mL min-1 was used as the carrier gas, and the split ratio was 100:1. The separated compounds were analyzed by the mass spectrometer. The EI ionization energy was 70 eV, and the transfer line temperature was 300 C. Ion source temperature was 230 C, and quadrupole temperature was 150 C. The mass spectra were obtained from m/z 30 to 500, and solvent delay time was 3.9 min. The pyrolysis products were identified by comparison between the experimental mass spectrum and mass spectrum library (NIST 11) attached to the Py-GC/MS apparatus. All quantitative data were expressed by average values of the duplicate pyrolysis runs. For each product, its peak area% value obtained under different pyrolysis conditions can be compared to reveal the changing of its relative content among the detected products.General procedure: Py-GC/MS analysis used in this study has a Pyroprobe 5250T (CDS, Analytical Inc., ) connected directly to a GC/MS (Agilent, 7890A/5975C). About 0.20 mg of each sample was centered in a 25-mm quartz tube and pyrolyzed isothermally at the designed temperatures for 10 s. Thepyrolysis temperatures were set up at 300, 450, 600, 750 and 900 C, respectively. The temperature of the reactor was initially set at 50 C and heated nominally at the rate of 10 C ms-1. The pyrolysis atmospheres were both in nitrogen (0% oxygen) and in the mixture gases of oxygen (9%) and nitrogen (91%) at 300, 450, 600 C, and in nitrogen at 750 and 900 C only. The final pyrolysis vapor was directly transferred to the GC/MS and analyzed. The chromatographic separation was performed using a DB-5MS fused silica capillary column (60 m x 250 mum id x 0.25 mum df, Agilent). The injector temperature was kept at 300 C. Initial oven temperature was set at 50 C, then heated to 80 C at the rate of 6 C min-1, followed by a heating rate of 4 C min-1 to 110 C , held there for 2 min and finished at 250 C with a rate of 5 C min-1. Helium at a constant flow rate of 1 mL min-1 was used as the carrier gas, and the split ratio was 100:1. The separated compounds were analyzed by the mass spectrometer. The EI ionization energy was 70 eV, and the transfer line temperature was 300 C. Ion source temperature was 230 C, and quadrupole temperature was 150 C. The mass spectra were obtained from m/z 30 to 500, and solvent delay time was 3.9 min. The pyrolysis products were identified by comparison between the experimental mass spectrum and mass spectrum library (NIST 11) attached to the Py-GC/MS apparatus. All quantitative data were expressed by average values of the duplicate pyrolysis runs. For each product, its peak area% value obtained under different pyrolysis conditions can be compared to reveal the changing of its relative content among the detected products.General procedure: Py-GC/MS analysis used in this study has a Pyroprobe 5250T (CDS, Analytical Inc., ) connected directly to a GC/MS (Agilent, 7890A/5975C). About 0.20 mg of each sample was centered in a 25-mm quartz tube and pyrolyzed isothermally at the designed temperatures for 10 s. Thepyrolysis temperatures were set up at 300, 450, 600, 750 and 900 C, respectively. The temperature of the reactor was initially set at 50 C and heated nominally at the rate of 10 C ms-1. The pyrolysis atmospheres were both in nitrogen (0% oxygen) and in the mixture gases of oxygen (9%) and nitrogen (91%) at 300, 450, 600 C, and in nitrogen at 750 and 900 C only. The final pyrolysis vapor was directly transferred to the GC/MS and analyzed. The chromatographic separation was performed using a DB-5MS fused silica capillary column (60 m x 250 mum id x 0.25 mum df, Agilent). The injector temperature was kept at 300 C. Initial oven temperature was set at 50 C, then heated to 80 C at the rate of 6 C min-1, followed by a heating rate of 4 C min-1 to 110 C , held there for 2 min and finished at 250 C with a rate of 5 C min-1. Helium at a constant flow rate of 1 mL min-1 was used as the carrier gas, and the split ratio was 100:1. The separated compounds were analyzed by the mass spectrometer. The EI ionization energy was 70 eV, and the transfer line temperature was 300 C. Ion source temperature was 230 C, and quadrupole temperature was 150 C. The mass spectra were obtained from m/z 30 to 500, and solvent delay time was 3.9 min. The pyrolysis products were identified by comparison between the experimental mass spectrum and mass spectrum library (NIST 11) attached to the Py-GC/MS apparatus. All quantitative data were expressed by average values of the duplicate pyrolysis runs. For each product, its peak area% value obtained under different pyrolysis conditions can be compared to reveal the changing of its relative content among the detected products.EXAMPLE IV Preparation Of (R, S)-2-(2-Hydroxy-2-phenylethyl)-3-isobutylpyrazine A reaction of

Molecular Weight:150.22
XLogP3:2
Hydrogen Bond Acceptor Count:2
Rotatable Bond Count:2
Exact Mass:150.115698455
Monoisotopic Mass:150.115698455
Topological Polar Surface Area:25.8
Heavy Atom Count:11
Complexity:112
Covalently-Bonded Unit Count:1
Compound Is Canonicalized:Yes