Highly efficient synthesis of 2,5-disubstituted pyrazines from (Z)-β-haloenol acetates.
Chen, Zhengwang; Ye, Dongnai; Xu, Guohai; Ye, Min; Liu, Liangxian; Organic & biomolecular chemistry 11 (2013) 6699–6702; doi:10.1039/c3ob41164h

data_7153086
_publ_section_title
;
 Highly efficient synthesis of 2,5-disubstituted pyrazines from
 (Z)-\b-haloenol acetates.
;
_journal_issue                   39
_journal_name_full               'Organic &amp; biomolecular chemistry'
_journal_page_first              6699
_journal_page_last               6702
_journal_paper_doi               10.1039/c3ob41164h
_journal_volume                  11
_journal_year                    2013
_chemical_formula_moiety         'C16 H10 F2 N2'
_chemical_formula_sum            'C16 H10 F2 N2'
_chemical_formula_weight         268.26
_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                 90.41(3)
_cell_angle_gamma                90.00
_cell_formula_units_Z            2
_cell_length_a                   3.8013(7)
_cell_length_b                   11.882(3)
_cell_length_c                   13.310(4)
_cell_measurement_reflns_used    2895
_cell_measurement_temperature    293(2)
_cell_measurement_theta_max      27.89
_cell_measurement_theta_min      2.35
_cell_volume                     601.2(3)
_computing_cell_refinement       RAPID-AUTO
_computing_data_collection       'RAPID-AUTO (Rigaku, 1998)'
_computing_data_reduction        'CrystalStructure (Rigaku/MSC, 2002)'
_computing_molecular_graphics    'ORTEPII (Johnson, 1976)'
_computing_publication_material  SHELXL97
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 2008)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 2008)'
_diffrn_ambient_temperature      293(2)
_diffrn_measured_fraction_theta_full 0.993
_diffrn_measured_fraction_theta_max 0.993
_diffrn_measurement_device_type  'Rigaku/MSC Mercury CCD'
_diffrn_measurement_method       \w
_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  0.0872
_diffrn_reflns_av_sigmaI/netI    0.0624
_diffrn_reflns_limit_h_max       4
_diffrn_reflns_limit_h_min       -4
_diffrn_reflns_limit_k_max       14
_diffrn_reflns_limit_k_min       -14
_diffrn_reflns_limit_l_max       15
_diffrn_reflns_limit_l_min       -15
_diffrn_reflns_number            4620
_diffrn_reflns_theta_full        25.20
_diffrn_reflns_theta_max         25.20
_diffrn_reflns_theta_min         3.06
_diffrn_standards_number         0
_exptl_absorpt_coefficient_mu    0.111
_exptl_absorpt_correction_T_max  0.988
_exptl_absorpt_correction_T_min  0.975
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   '(Jacobson, 1998)'
_exptl_crystal_colour            colorless
_exptl_crystal_density_diffrn    1.482
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       block
_exptl_crystal_F_000             276
_exptl_crystal_size_max          0.30
_exptl_crystal_size_mid          0.26
_exptl_crystal_size_min          0.22
_refine_diff_density_max         0.177
_refine_diff_density_min         -0.223
_refine_diff_density_rms         0.055
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   0.986
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     91
_refine_ls_number_reflns         1078
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      0.986
_refine_ls_R_factor_all          0.1215
_refine_ls_R_factor_gt           0.0599
_refine_ls_shift/su_max          0.000
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w=1/[\s^2^(Fo^2^)+(0.0348P)^2^+0.6216P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1097
_refine_ls_wR_factor_ref         0.1392
_reflns_number_gt                602
_reflns_number_total             1078
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            c3ob41164h.txt
_cod_data_source_block           2
_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 
;
_cod_original_sg_symbol_H-M      'P 21/c '
_cod_database_code               7153086