Base-Promoted Reactions of Dichlorocarbene Adducts of Cyclic Enamines: A New Route to Annulated Pyrroles (original) (raw)
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Supplementary Information Chem. Commun. 2012 D'Errico et al
All the reagents were obtained from commercial sources (Sigma-Aldrich) and were used without further purification. 1 H and 13 C-NMR spectra were acquired on a Varian Mercury Plus 400 MHz and on a Varian Unit Inova 700 MHz in CD 3 OD or CDCl 3 . Chemical shifts are reported in parts per million (δ) relative to the residual solvent signals: CD 2 HOD 3.31 and CHCl 3 7.27 for 1 H-NMR; CD 2 HOD 49.0 and CHCl 3 77.0 for 13 C-NMR. 1 H-NMR chemical shifts were assigned by 2D NMR experiments. The abbreviations s, bs, d, dd and m stand for singlet, broad singlet, doublet, doublet of doublets and multiplet, respectively. HPLC analyses and purifications were carried out on a Jasco UP-2075 Plus pump equipped with a Jasco UV-2075 Plus UV detector using a 4.60 x 150 mm LUNA (Phenomenex) silica column (particle size 5 µm) eluted with a linear gradient of MeOH in AcOEt (from 0 to 5% in 15 min, flow 1.0 mL min -1 , system A), with a linear gradient of AcOEt in n-hexane (from 0 to 100% in 30 min, flow 1.0 mL min -1 , system B) or using a 4.8 x 150 mm C-18 reverse-phase column (particle size 5 µm) eluted with a linear gradient of MeOH in H 2 O (from 0 to 100% in 30 min, flow 1.3 mL min -1 , system C). UV spectra were recorded on a Jasco V-530 UV spectrophotometer. High Resolution MS spectra were recorded on a Bruker APEX II FT-ICR mass spectrometer using electrospray ionization (ESI) technique in positive mode. Elemental analyses were performed on a Thermo Finnigan Flash EA 1112 CHN analyser. IR spectra were recorded on a Jasco FT-IR 430 spectrophotometer. Optical rotations were determined on a Jasco polarimeter using a 1 dm cell at 25 °C; concentrations are in g/100 mL. Preparative PLC chromatography was performed using F254 silica gel plates (0.5 mm thick, Merck). Analytical TLC analyses were performed using F254 silica gel plates (0.2 mm thick, Merck). TLC spots were detected under UV light (254 nm). For MTS assays the UV absorbance at 490 nm was read using a Beckman Anthos 96 well Microplate Reader.
The Journal of Organic Chemistry, 1992
To a stirred and cooled (-100 OC) solution of 4 (40 mg, 0.32 mmol) in THF (4 mL) was added via cannula a cooled (-100 OC) LDA solution prepared from i-PrzNH (49 pL, 0.34 mmol) and BuLi (1.48 M in hexane, 0.22 mL, 0.33 mmol) in THF (1.5 mL). After 8 min, dry DMPU (77 pL, 0.64 "01) was introduced, and to the mixture was added a solution of 63 (63 mg, 0.107 "01) in THF (1.5 mL) over a 2-min period.
Chemistry of Materials, 1990
The synthesis of tert-butylarsine-d2 from tert-butylarsenic dichloride and LiAIDl is described. No resonances at 2.65 ppm (from AsH2) are observed in the 'H NMR spectrum, indicating the isotopic purity is greater than 95%. The pyrolyses of tert-butylarsine and tert-butylarsine-d2 were studied by using a flow reactor operated between 425 and 550 "C at total pressures of 0.001,5, and 700 Torr. At 5 and 700 Torr, nitrogen was used as the carrier gas. The volatile products of the reaction were trapped in a liquid nitrogen cooled trap, transferred under vacuum into an NMR tube, and quantitatively analyzed by using 'H NMR spectroscopy. Three important results from the study are (1) the isobutane produced during the pyrolysis of tert-butylarsine-d2 was Me3CD, (2) C@es was proven not to be a product of the reaction, (3) isobutane was found to be the major product at atmospheric pressure, while isobutene was predominant at low pressures in agreement with previous studies. These data allow us to evaluate the possible mechanisms for the pyrolysis and discard a mechanism involving radical non-chain reactions.
J. Serb. Chem. Soc. 82 (3) 241–251 (2017).pdf
Journal of the Serbian Chemical Society , 2017
A series of novel bis(1,2,3-triazoles) derivatives 7a–m were synthesized by the 1,3-dipolar cycloaddition (click-reaction) of 1-methyl-3,5-bis(2-(prop-2-yn-1-yloxy)phenyl)-4,5-dihydro-1H-pyrazole (5) with various aralkyl azides 6a–m in the presence of sodium ascorbate and copper sulphate with good yields. The required precursor 5 was synthesized by reacting (E)-1,3-bis(2-hydroxyphenyl)prop-2-en-1-one (3) with methylhydrazine hydrate via 2,2′-(1-methyl-4,5-dihydro-1H-pyrazole-3,5-diyl)diphenol 4, followed by reaction with propargyl bromide. The homogeneity of all the newly synthesized compounds was checked by TLC. The IR, NMR, mass spectral data and elemental analysis were in accord with the assigned structure. The title compounds were evaluated for their antibacterial activity against various bacterial strains, i.e., Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus and Bacillus subtilis; compounds 7f–7h and 7j were found to be moderately active against the bacteria, when compared with that of the standard drug. Furthermore, the same library of compounds was evaluated for their antioxidant activity using the nitric oxide radical scavenging activity. The results of the study showed that compounds 7e–7h and 7k–7m showed good radical scavenging activity.
Sulfur-33 NMR spectra of sulfonic acids and sulfonate salts
Journal of Organic Chemistry, 1985
Anisoyl peroxide with 90% I3C in the carbonyl groups was made from the labeled acid and ethereal HzOz by the dicyclohexylcarbodiimide method:l0 mp 123.5-124 "C (lit.' O mp 124.5-125 "C). Anisoyl Anisyl Carbonate (CIN). To 3.20 g (0.0176 mol) of diphosgene was added dropwise with stirring 8.8 mL of 0.2 M aqueous sodium p-methoxyphenohte during 30 min. At this point 10 mL of ether was added and the stirring continued for 10 min. After adding a further 15 mL of ether and 10 mL of HzO and shaking, the water layer was removed and discarded. Then 1.8 g of triethylamine in 10 mL of CHzClz was added dropwise with stirring during 10 min to a mixture consisting of the ether solution, 2.70 g of anisic acid, and 25 mL of CH,Cl,. After more water and ether were added, the mixture was shaken and the organic layer was washed with water and twice with aqueous NaZCO3 and dried over Na2S04. The ether was then removed by rotary evaporation and the residue crystallized from benzene: yield, 1.8 g (34%); mp 92-94 OC dec (gas evolution); IR 1810 cm-' (s), 1740 cm-' (m). Dianisyl Carbonate. A 12-mL sample of 0.2 M sodium pmethoxyphenolate was stirred with 1.62 g of diphosgene for 30 min. Water and CH2Clz were added and the precipitate that had formed dissolved in the CHzCl,. This solution was washed twice with water and dried over NazS04, and the solvent was removed by rotary evaporation. The residue was crystallized from benzene/pentane: yield 0.5 g; mp 85-89 "C, main GLC peak 99 area %; IR (CH,Cl,) 1800 cm-' (shldr), 1770 cm-' (s).
Rapid Communications in Mass Spectrometry, 1988
actions are absent in the trans-anellated isomer (6). On the other hand, here the free electron pair of the oxygen atom can assist either C4-C4a or N-C2 bondbreaking, leading to the formation of ion [C8HI$4]+. The same stereo-electronic factor is probably responsible for the fact that isomer 6 is the only compound studied which loses CHzO in any significant amount. The ion [C9HI7N]+' so formed then eliminates C6H; forming the ion [C3HsN]+ at mlz 58. The abundance of this ion, which is also formed from mlr 126, mlz 124 and mlz 110 ions, reflects the most salient difference between the spectra of compounds 5 and 6. The compounds studied could not be differentiated based on their ammonia or isobutane chemical ionization spectra. Under these conditions practically the only ions observed were of formula [M + HI+ probably due to enhanced basicity of the nitrogen atom caused by its methyl substitution. EXPERIMENTAL Synthesis and structural characterization of the compounds studied has been presented elsewhere.' All measurements were made on a Jeol JMS-D300 mass spectrometer (Joensuu) equipped with a JMA-2000H data system or on a VG Analytical MM 7070E mass spectrometer (Turku) equipped with a VG 11-250 data system. Typical source conditions were: temperature 443 K, electron energy 70 eV, ionization current 300 FA and acceleration voltage 3 kV. Samples were introduced through heated inlet systems at about 323 K (7070E) and 363K (JMS-D300). No differences in the spectra were observed when a gas chromatography inlet system was used. Accurate mass measurements were made at a resolving power of 5000. Metastable ion analyses were performed with linked scans at constant BlE. In CID experiments helium was added to the first field-free region so that transmission of the main beam was reduced to 33% of its value in the absence of collision gas.