Pyrrolo[1,2-a]quinoxalines: novel synthesis via annulation of 2-alkylquinoxalines.
Ammermann, Sven; Hrib, Christian; Jones, Peter G.; du Mont, Wolf-Walther; Kowalsky, Wolfgang; Johannes, Hans-Hermann; Organic letters 14 (2012) 5090–5093; doi:10.1021/ol302348v

data_1508681
_publ_section_title
;
 Pyrrolo[1,2-a]quinoxalines: novel synthesis via annulation of
 2-alkylquinoxalines.
;
_journal_issue                   19
_journal_name_full               'Organic letters'
_journal_page_first              5090
_journal_page_last               5093
_journal_paper_doi               10.1021/ol302348v
_journal_volume                  14
_journal_year                    2012
_chemical_formula_sum            'C19 H16 N2'
_chemical_formula_weight         272.34
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_symmetry_space_group_name_Hall  '-P 2yn'
_symmetry_space_group_name_H-M   'P 1 21/n 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                 103.626(3)
_cell_angle_gamma                90.00
_cell_formula_units_Z            4
_cell_length_a                   8.3778(4)
_cell_length_b                   11.2485(6)
_cell_length_c                   15.3805(8)
_cell_measurement_reflns_used    9847
_cell_measurement_temperature    100(2)
_cell_measurement_theta_max      31.07
_cell_measurement_theta_min      2.27
_cell_volume                     1408.63(13)
_computing_cell_refinement       'Bruker APEX2'
_computing_data_collection       'Bruker APEX2'
_computing_data_reduction        'Bruker APEX2'
_computing_molecular_graphics    'Siemens XP'
_computing_publication_material  SHELXL-97
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 1990)'
_diffrn_ambient_temperature      100(2)
_diffrn_measured_fraction_theta_full 1.000
_diffrn_measured_fraction_theta_max 0.998
_diffrn_measurement_device_type  'Bruker APEX2 CCD area detector'
_diffrn_measurement_method       'phi and omega scans'
_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  0.0273
_diffrn_reflns_av_sigmaI/netI    0.0123
_diffrn_reflns_limit_h_max       12
_diffrn_reflns_limit_h_min       -12
_diffrn_reflns_limit_k_max       16
_diffrn_reflns_limit_k_min       -16
_diffrn_reflns_limit_l_max       22
_diffrn_reflns_limit_l_min       -22
_diffrn_reflns_number            51880
_diffrn_reflns_theta_full        30.50
_diffrn_reflns_theta_max         31.12
_diffrn_reflns_theta_min         2.55
_exptl_absorpt_coefficient_mu    0.076
_exptl_absorpt_correction_type   none
_exptl_absorpt_process_details   none
_exptl_crystal_colour            'pale yellow'
_exptl_crystal_density_diffrn    1.284
_exptl_crystal_density_meas      ?
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       'irregular tablet'
_exptl_crystal_F_000             576
_exptl_crystal_size_max          0.30
_exptl_crystal_size_mid          0.30
_exptl_crystal_size_min          0.20
_refine_diff_density_max         0.474
_refine_diff_density_min         -0.226
_refine_diff_density_rms         0.052
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.046
_refine_ls_hydrogen_treatment    'rigid methyls, others riding'
_refine_ls_matrix_type           full
_refine_ls_number_parameters     192
_refine_ls_number_reflns         4528
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.046
_refine_ls_R_factor_all          0.0459
_refine_ls_R_factor_gt           0.0407
_refine_ls_shift/su_max          0.001
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w=1/[\s^2^(Fo^2^)+(0.0721P)^2^+0.3705P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1134
_refine_ls_wR_factor_ref         0.1190
_reflns_number_gt                4001
_reflns_number_total             4528
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            ol302348v_si_002.cif
_cod_data_source_block           schab
_cod_depositor_comments
;
The following automatic conversions were performed:

'_symmetry_cell_setting' value 'Monoclinic' changed to 'monoclinic'
according to /home/saulius/struct/CIF-dictionaries/cif_core.dic
dictionary named 'cif_core.dic' version 2.4.2 from 2011-04-26.

Automatic conversion script
Id: cif_fix_values 1891 2012-01-12 08:04:46Z andrius 

The following automatic conversions were performed:

'_exptl_crystal_density_meas' value 'not measured' was changed to '?'
- the value is perceived as not measured.

Automatic conversion script
Id: cif_fix_values 3008 2015-01-20 13:52:24Z robertas 
;
_cod_original_cell_volume        1408.63(12)
_cod_original_sg_symbol_H-M      'P 21/n'
_cod_database_code               1508681