Studies on the Regioselective Nucleophilic Aromatic Substitution (SNAr) Reaction of 2-Substituted 3,5-Dichloropyrazines
Scales, Stephanie; Johnson, Sarah; Hu, Qiyue; Do, Quyen-Quyen; Richardson, Paul; Wang, Fen; Braganza, John; Ren, Shijian; Wan, Yadong; Zheng, Baojiang; Faizi, Darius; McAlpine, Indrawan; Organic Letters 15 (2013) 2156–; doi:10.1021/ol4006695

data_1511937
_publ_section_title
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 Studies on the Regioselective Nucleophilic Aromatic Substitution (SNAr)
 Reaction of 2-Substituted 3,5-Dichloropyrazines
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_journal_issue                   9
_journal_name_full               'Organic Letters'
_journal_page_first              2156
_journal_paper_doi               10.1021/ol4006695
_journal_volume                  15
_journal_year                    2013
_chemical_formula_sum            'C7 H7 Cl F3 N3 O'
_chemical_formula_weight         241.61
_space_group_IT_number           61
_symmetry_cell_setting           orthorhombic
_symmetry_space_group_name_Hall  '-P 2ac 2ab'
_symmetry_space_group_name_H-M   'P b c a'
_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                 90.00
_cell_angle_gamma                90.00
_cell_formula_units_Z            16
_cell_length_a                   16.3661(6)
_cell_length_b                   6.7959(2)
_cell_length_c                   33.9544(12)
_cell_measurement_reflns_used    7832
_cell_measurement_temperature    90(2)
_cell_measurement_theta_max      68.14
_cell_measurement_theta_min      3.75
_cell_volume                     3776.5(2)
_computing_cell_refinement       'Bruker SAINT'
_computing_data_collection       'Bruker APEX2'
_computing_data_reduction        'Bruker SAINT'
_computing_molecular_graphics    'Bruker SHELXTL'
_computing_publication_material  'Bruker SHELXTL'
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 2008)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 2008)'
_diffrn_ambient_temperature      90(2)
_diffrn_measured_fraction_theta_full 0.988
_diffrn_measured_fraction_theta_max 0.980
_diffrn_measurement_device_type  'Bruker APEX-II CCD'
_diffrn_measurement_method       '\f and \w scans'
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_source         'fine-focus sealed tube'
_diffrn_radiation_type           CuK\a
_diffrn_radiation_wavelength     1.54178
_diffrn_reflns_av_R_equivalents  0.0405
_diffrn_reflns_av_sigmaI/netI    0.0307
_diffrn_reflns_limit_h_max       19
_diffrn_reflns_limit_h_min       -15
_diffrn_reflns_limit_k_max       7
_diffrn_reflns_limit_k_min       -8
_diffrn_reflns_limit_l_max       40
_diffrn_reflns_limit_l_min       -40
_diffrn_reflns_number            16261
_diffrn_reflns_theta_full        60.00
_diffrn_reflns_theta_max         68.33
_diffrn_reflns_theta_min         3.75
_exptl_absorpt_coefficient_mu    3.894
_exptl_absorpt_correction_T_max  0.7458
_exptl_absorpt_correction_T_min  0.5927
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   SADASB
_exptl_crystal_colour            Colorless
_exptl_crystal_density_diffrn    1.700
_exptl_crystal_density_meas      ?
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       Needle
_exptl_crystal_F_000             1952
_exptl_crystal_size_max          0.15
_exptl_crystal_size_mid          0.11
_exptl_crystal_size_min          0.08
_refine_diff_density_max         0.260
_refine_diff_density_min         -0.314
_refine_diff_density_rms         0.052
_refine_ls_extinction_coef       0.00019(3)
_refine_ls_extinction_expression Fc^*^=kFc[1+0.001xFc^2^\l^3^/sin(2\q)]^-1/4^
_refine_ls_extinction_method     SHELXL
_refine_ls_goodness_of_fit_ref   1.028
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     274
_refine_ls_number_reflns         3394
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.028
_refine_ls_R_factor_all          0.0368
_refine_ls_R_factor_gt           0.0300
_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^)+(0.0379P)^2^+1.6004P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0723
_refine_ls_wR_factor_ref         0.0760
_reflns_number_gt                2950
_reflns_number_total             3394
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            ol4006695_si_001.cif
_cod_data_source_block           chloro_methoxy_trifluoroethyl_pyrazinamine
_cod_depositor_comments
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The following automatic conversions were performed:

'_symmetry_cell_setting' value 'Orthorhombic' changed to
'orthorhombic' 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_sg_symbol_H-M      Pbca
_cod_database_code               1511937