Copper catalyzed synthesis of fused benzimidazolopyrazine derivatives via tandem benzimidazole formation/annulation of δ-alkynyl aldehyde.
Ramesh, Subburethinam; Kr Ghosh, Suman; Nagarajan, Rajagopal; Organic & biomolecular chemistry 11 (2013) 7712–7720; doi:10.1039/c3ob41044g

data_7153133
_publ_section_title
;
 Copper catalyzed synthesis of fused benzimidazolopyrazine derivatives via
 tandem benzimidazole formation/annulation of \d-alkynyl aldehyde.
;
_journal_issue                   44
_journal_name_full               'Organic &amp; biomolecular chemistry'
_journal_page_first              7712
_journal_page_last               7720
_journal_paper_doi               10.1039/c3ob41044g
_journal_volume                  11
_journal_year                    2013
_chemical_formula_moiety         'C18 H13 Br N4'
_chemical_formula_sum            'C18 H13 Br N4'
_chemical_formula_weight         365.23
_chemical_name_systematic
;
?
;
_space_group_IT_number           14
_symmetry_cell_setting           monoclinic
_symmetry_space_group_name_Hall  '-P 2ybc'
_symmetry_space_group_name_H-M   'P 1 21/c 1'
_atom_sites_solution_hydrogens   geom
_atom_sites_solution_primary     direct
_atom_sites_solution_secondary   difmap
_audit_creation_method           SHELXL-97
_cell_angle_alpha                90.00
_cell_angle_beta                 94.664(10)
_cell_angle_gamma                90.00
_cell_formula_units_Z            4
_cell_length_a                   7.5297(8)
_cell_length_b                   15.7552(16)
_cell_length_c                   12.3971(16)
_cell_measurement_reflns_used    470
_cell_measurement_temperature    298
_cell_measurement_theta_max      28.8635
_cell_measurement_theta_min      3.0005
_cell_volume                     1465.8(3)
_computing_cell_refinement
;
CrysAlisPro, Agilent Technologies,
Version 1.171.35.19 (release 27-10-2011 CrysAlis171 .NET)
(compiled Oct 27 2011,15:02:11)
;
_computing_data_collection
;
CrysAlisPro, Agilent Technologies,
Version 1.171.35.19 (release 27-10-2011 CrysAlis171 .NET)
(compiled Oct 27 2011,15:02:11)
;
_computing_data_reduction
;
CrysAlisPro, Agilent Technologies,
Version 1.171.35.19 (release 27-10-2011 CrysAlis171 .NET)
(compiled Oct 27 2011,15:02:11)
;
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 1990)'
_diffrn_ambient_temperature      298
_diffrn_measured_fraction_theta_full 0.676
_diffrn_measured_fraction_theta_max 0.676
_diffrn_measurement_device_type  'Xcalibur, Eos, Gemini'
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_source         'fine-focus sealed tube'
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.0420
_diffrn_reflns_av_sigmaI/netI    0.1015
_diffrn_reflns_limit_h_max       5
_diffrn_reflns_limit_h_min       -9
_diffrn_reflns_limit_k_max       19
_diffrn_reflns_limit_k_min       -7
_diffrn_reflns_limit_l_max       15
_diffrn_reflns_limit_l_min       -10
_diffrn_reflns_number            3007
_diffrn_reflns_theta_full        26.37
_diffrn_reflns_theta_max         26.37
_diffrn_reflns_theta_min         3.01
_exptl_absorpt_coefficient_mu    2.809
_exptl_absorpt_correction_T_max  1.00000
_exptl_absorpt_correction_T_min  0.07869
_exptl_absorpt_correction_type   multi-scan
_exptl_crystal_colour            COLOURLESS
_exptl_crystal_density_diffrn    1.655
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       NEEDLE
_exptl_crystal_F_000             736
_exptl_crystal_size_max          0.22
_exptl_crystal_size_mid          0.20
_exptl_crystal_size_min          0.12
_refine_diff_density_max         0.396
_refine_diff_density_min         -0.327
_refine_diff_density_rms         0.063
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   0.974
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     210
_refine_ls_number_reflns         2035
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      0.974
_refine_ls_R_factor_all          0.1224
_refine_ls_R_factor_gt           0.0614
_refine_ls_shift/su_max          0.007
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w=1/[\s^2^(Fo^2^)+(0.0065P)^2^+0.0000P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0654
_refine_ls_wR_factor_ref         0.0843
_reflns_number_gt                1160
_reflns_number_total             2035
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            c3ob41044g.txt
_cod_data_source_block           rn101c
_cod_database_code               7153133