Regioselective annulation of nitrosopyridine with alkynes: straightforward synthesis of N-oxide-imidazopyridines
Srimanta Manna; Rishikesh Narayan; Christopher Golz; Carsten Strohmann; Andrey P. Antonchick; Chem.Commun. 51 (2015) 6119–; doi:10.1039/C5cc00533G

data_7116877
_publ_section_title
;
 Regioselective annulation of nitrosopyridine with alkynes:
 straightforward synthesis of N-oxide-imidazopyridines
;
_journal_name_full               Chem.Commun.
_journal_page_first              6119
_journal_paper_doi               10.1039/C5cc00533G
_journal_volume                  51
_journal_year                    2015
_chemical_formula_moiety         'C19 H17 Br N2 O3'
_chemical_formula_sum            'C19 H17 Br N2 O3'
_chemical_formula_weight         401.25
_chemical_name_systematic
;
6-nitro-2,3-diphenylimidazo[1,2-a]pyridine 1-oxide
;
_space_group_IT_number           19
_symmetry_cell_setting           orthorhombic
_symmetry_Int_Tables_number      19
_symmetry_space_group_name_Hall  'P 2ac 2ab'
_symmetry_space_group_name_H-M   'P 21 21 21'
_atom_sites_solution_hydrogens   mixed
_audit_creation_date             2014-07-16T14:39:06-00:00
_audit_creation_method           'WinGX routine CIF_UPDATE'
_audit_update_record
;
2014-08-07 deposited with the CCDC.
2015-02-25 downloaded from the CCDC.
;
_cell_angle_alpha                90
_cell_angle_beta                 90
_cell_angle_gamma                90
_cell_formula_units_Z            4
_cell_length_a                   5.6130(4)
_cell_length_b                   16.0480(14)
_cell_length_c                   18.9931(15)
_cell_measurement_reflns_used    5561
_cell_measurement_temperature    173(2)
_cell_measurement_theta_max      23.802
_cell_measurement_theta_min      2.465
_cell_volume                     1710.8(2)
_computing_structure_refinement  'SHELXL-2013 (Sheldrick, 2013)'
_diffrn_ambient_temperature      173(2)
_diffrn_measured_fraction_theta_full 0.998
_diffrn_measured_fraction_theta_max 0.999
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.1113
_diffrn_reflns_Laue_measured_fraction_full 0.998
_diffrn_reflns_Laue_measured_fraction_max 0.999
_diffrn_reflns_limit_h_max       6
_diffrn_reflns_limit_h_min       -6
_diffrn_reflns_limit_k_max       19
_diffrn_reflns_limit_k_min       -19
_diffrn_reflns_limit_l_max       23
_diffrn_reflns_limit_l_min       -23
_diffrn_reflns_number            54577
_diffrn_reflns_point_group_measured_fraction_full 0.999
_diffrn_reflns_point_group_measured_fraction_max 0.999
_diffrn_reflns_theta_full        25.242
_diffrn_reflns_theta_max         25.997
_diffrn_reflns_theta_min         2.492
_exptl_absorpt_coefficient_mu    2.424
_exptl_absorpt_correction_T_max  1
_exptl_absorpt_correction_T_min  0.80289
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details
;
        CrysAlisPro, Agilent Technologies,
        Version 1.171.37.31 (release 14-01-2014 CrysAlis171 .NET)
        (compiled Jan 14 2014,18:38:05)
        Empirical absorption correction using spherical harmonics,
 implemented in SCALE3 ABSPACK scaling algorithm.
;
_exptl_crystal_colour            colourless
_exptl_crystal_density_diffrn    1.558
_exptl_crystal_description       needle
_exptl_crystal_F_000             816
_exptl_crystal_recrystallization_method 'Re-crystallisation from solvent: water'
_exptl_crystal_size_max          0.401
_exptl_crystal_size_mid          0.043
_exptl_crystal_size_min          0.023
_refine_diff_density_max         0.336
_refine_diff_density_min         -0.235
_refine_diff_density_rms         0.066
_refine_ls_abs_structure_details
;
 Flack x determined using 1026 quotients [(I+)-(I-)]/[(I+)+(I-)]
 (Parsons and Flack (2004), Acta Cryst. A60, s61).
;
_refine_ls_abs_structure_Flack   -0.026(6)
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.021
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     242
_refine_ls_number_reflns         3355
_refine_ls_number_restraints     4
_refine_ls_restrained_S_all      1.022
_refine_ls_R_factor_all          0.0542
_refine_ls_R_factor_gt           0.0358
_refine_ls_shift/su_max          0.033
_refine_ls_shift/su_mean         0.002
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'w=1/[\s^2^(Fo^2^)+(0.0368P)^2^+0.0146P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0688
_refine_ls_wR_factor_ref         0.0753
_reflns_number_gt                2765
_reflns_number_total             3355
_reflns_threshold_expression     'I > 2\s(I)'
_cod_data_source_file            c5cc00533g2.cif
_cod_data_source_block           5965
_cod_database_code               7116877
_shelx_estimated_absorpt_t_min   0.443
_shelx_estimated_absorpt_t_max   0.946