Compound 26
3-nitrobenzazetidine
From: Benzazetidine synthesis via palladium-catalysed intramolecular C−H amination
View in PubChem | 1H NMR | 13C NMR | MDL Molfile | ChemDraw
Compound data: CIF
Compound data: FCF
Synthetic procedure: See article for the definitive version of this procedure and for full experimental details.
Compound 13N (50 mg, 0.19 mmol, 1.0 equiv) was dissolved in a mixture of THF/MeOH/H2O (3/1/1, 1 mL) and NaOH (12 mg, 0.29 mmol, 1.5 equiv) was added. The resulting mixture was stirred at room temperature for 5 hours. After removal of the organic solvent under reduced pressure the aqueous phase was extracted with DCM. The combined organic layer was washed with brine, dried over anhydrous Na2SO4, and concentrated in vacuo. The residue was purified by silica gel flash chromatography to give the desired product in 88% yield. Single crystals for X-ray studies were grown by slow evaporation of a solution of 26 in a mixture of hexane and ethyl acetate (2:1). (Rf = 0.5, 30% Ethyl Acetate in Hexanes). 1H NMR (CDCl3, 400 MHz) δ 7.61 (d, J = 8.6 Hz, 1H), 7.35 (dd, J = 8.4, 7.7 Hz, 1H), 6.95 (d, J = 7.6 Hz, 1H), 4.93 (s, 2H), 4.46 (s, 1H); 13C NMR (CDCl3, 100 MHz) δ 157.76, 141.44, 129.85, 129.39, 116.34, 114.46, 56.12; HRMS Calcd for C7H7N2O2 [M+H+]: 151.0502, found: 151.0511. IR (film) 3257, 3094, 2953, 1516, 1355, 1288, 734, 671 cm-1. The X-ray crystal structure is deposited in the Cambridge Crystallographic Data Centre CCDC 1430312. A yellow needle shaped crystal of compound 26 (C7H6N2O2) with approximate dimensions 0.20 x 0.18 x 0.12 mm, was used for the X-ray crystallographic analysis. The X-ray intensity data were measured at 298(2) K, on a Rigaku 007 Saturn 70 CCD area detector system with a graphite monochromator and a MoKα fine-focus sealed tube (λ = 0.71073Å). The integration of the data using a Monoclinic unit cell yielded a total of 5212 reflections to a maximum θ angle of 25.08o, of which 1232 were unique, completeness = 98.8%, Rint = 0.0481. The final cell constants: a = 13.373(3) Å, b = 3.9583(8) Å, c = 14.290(3) Å, α = 90°, β = 112.31(4)°, γ = 90°, volume = 699.8(2) Å3, are based upon the refinement of the XYZ-centroids of 1232 reflections above 20σ(I) with 2.65° <θ <25.08°. Analysis of the data showed negligible decay during data collection. Data were corrected for absorption effects using the Semi-empirical from equivalents. The ratio of minimum to maximum apparent transmission was 0.9915. The structure was solved and refined using the Full-matrix least-squares Software Package, using the space group P2(1)/n, with Z = 4 for the formula unit, C7H6N2O2. The final anisotropic full-matrix least-squares refinement on F2 with 104 variables converged at R1 = 5.58%, for the observed data and wR2 = 15.14% for all data. The goodness-of-fit was 1.055. The largest peak on the final difference map was 0.193 e-/Å3 and the largest hole was -163 e-/Å3. Based on the final model, the calculated density of the crystal is 1.425 Mg/m3 and F(000) amounts to 312 electrons.
