DBU-catalysed cascade nucleophilic addition/cyclization to access 7-nitro (ester) imidazo[1,2-<i>a</i>] pyridin-8-amines.
Nagineni, Devendra; Pranathi, Abburi Naga; Behera, Prakash Suman; Konderpu, Manasa; Sridhar, Balasubramanian; Kantevari, Srinivas; Organic & biomolecular chemistry 23 (2025) 8920–8927; doi:10.1039/d5ob01228g

data_7160721
_publ_section_title
;
 DBU-catalysed cascade nucleophilic addition/cyclization to access 7-nitro
 (ester) imidazo[1,2-<i>a</i>] pyridin-8-amines.
;
_journal_issue                   39
_journal_name_full               'Organic &amp; biomolecular chemistry'
_journal_page_first              8920
_journal_page_last               8927
_journal_paper_doi               10.1039/d5ob01228g
_journal_volume                  23
_journal_year                    2025
_chemical_formula_moiety         'C24 H23 N3 O3'
_chemical_formula_sum            'C24 H23 N3 O3'
_chemical_formula_weight         401.45
_space_group_crystal_system      monoclinic
_space_group_IT_number           14
_space_group_name_Hall           '-P 2yn'
_space_group_name_H-M_alt        'P 1 21/n 1'
_atom_sites_solution_hydrogens   mixed
_audit_creation_method           SHELXL-2019/3
_audit_update_record
;
2025-06-27 deposited with the CCDC.	2025-09-09 downloaded from the CCDC.
;
_cell_angle_alpha                90
_cell_angle_beta                 109.2138(19)
_cell_angle_gamma                90
_cell_formula_units_Z            4
_cell_length_a                   17.8977(10)
_cell_length_b                   6.7010(4)
_cell_length_c                   18.1820(10)
_cell_measurement_reflns_used    7713
_cell_measurement_temperature    294(2)
_cell_measurement_theta_max      24.4535
_cell_measurement_theta_min      2.2705
_cell_volume                     2059.1(2)
_computing_cell_refinement       '<i>SAINT</i> (Bruker, 2019)'
_computing_data_collection       '<i>APEX5</i> (Bruker, 2023)'
_computing_data_reduction        'Bruker SAINT'
_computing_molecular_graphics    'Bruker SHELXTL'
_computing_publication_material  'Bruker SHELXTL'
_computing_structure_refinement  'SHELXL-2018/3 (Sheldrick, 2019)'
_computing_structure_solution    'SHELXT 2018/2 (Sheldrick, 2019)'
_diffrn_ambient_temperature      294(2)
_diffrn_detector_area_resol_mean 7.391
_diffrn_measured_fraction_theta_full 0.999
_diffrn_measured_fraction_theta_max 0.999
_diffrn_measurement_device_type  'Bruker D8 VENTURE PHOTON III C14'
_diffrn_measurement_method       '\w and \f scans'
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.0433
_diffrn_reflns_av_unetI/netI     0.0346
_diffrn_reflns_Laue_measured_fraction_full 0.999
_diffrn_reflns_Laue_measured_fraction_max 0.999
_diffrn_reflns_limit_h_max       23
_diffrn_reflns_limit_h_min       -23
_diffrn_reflns_limit_k_max       8
_diffrn_reflns_limit_k_min       -8
_diffrn_reflns_limit_l_max       24
_diffrn_reflns_limit_l_min       -23
_diffrn_reflns_number            27944
_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         28.305
_diffrn_reflns_theta_min         1.949
_diffrn_source                   'Incoatec I\mS 3.0'
_exptl_absorpt_coefficient_mu    0.087
_exptl_absorpt_correction_T_max  0.7457
_exptl_absorpt_correction_T_min  0.7103
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details
;
 SADABS 2016/2: Krause, L., Herbst-Irmer, R., Sheldrick G.M. & Stalke D.,
 J. Appl. Cryst. 48 (2015) 3-10
;
_exptl_crystal_colour            colourless
_exptl_crystal_density_diffrn    1.295
_exptl_crystal_description       block
_exptl_crystal_F_000             848
_exptl_crystal_size_max          0.220
_exptl_crystal_size_mid          0.180
_exptl_crystal_size_min          0.160
_refine_diff_density_max         0.140
_refine_diff_density_min         -0.191
_refine_diff_density_rms         0.037
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.007
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     282
_refine_ls_number_reflns         5100
_refine_ls_number_restraints     2
_refine_ls_restrained_S_all      1.007
_refine_ls_R_factor_all          0.0793
_refine_ls_R_factor_gt           0.0471
_refine_ls_shift/su_max          0.000
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'w=1/[\s^2^(Fo^2^)+(0.0715P)^2^+0.1988P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1233
_refine_ls_wR_factor_ref         0.1452
_reflns_Friedel_coverage         0.000
_reflns_number_gt                3195
_reflns_number_total             5100
_reflns_threshold_expression     'I > 2\s(I)'
_cod_data_source_file            d5ob01228g3.cif
_cod_data_source_block           mo_VA303_0m
_cod_depositor_comments          'Adding full bibliography for 7160721.cif.'
_cod_original_sg_symbol_H-M      'P 21/n'
_cod_database_code               7160721
_shelx_shelxl_version_number     2019/3
_shelx_estimated_absorpt_t_min   0.981
_shelx_estimated_absorpt_t_max   0.986
_shelx_res_checksum              63588