Surprising orientation in ring synthesis of 3,5-dimethylpyrazin-2(1<i>H</i>)-one
Madeleine Helliwell; You Yun; John A. Joule; Acta Crystallographica Section E 62 (2006) o955–o956; doi:10.1107/S160053680600393X

data_2208241
_publ_section_title
;
 Surprising orientation in ring synthesis of
 3,5-dimethylpyrazin-2(1<i>H</i>)-one
;
_journal_coeditor_code           AT6083
_journal_issue                   3
_journal_name_full               'Acta Crystallographica Section E'
_journal_page_first              o955
_journal_page_last               o956
_journal_paper_doi               10.1107/S160053680600393X
_journal_volume                  62
_journal_year                    2006
_chemical_formula_iupac          'C6 H8 N2 O'
_chemical_formula_moiety         'C6 H8 N2 O'
_chemical_formula_sum            'C6 H8 N2 O'
_chemical_formula_weight         124.14
_chemical_melting_point          .144E-143
_chemical_name_systematic
;
3,5-dimethylpyrazin-2(1H)-one
;
_space_group_IT_number           14
_symmetry_cell_setting           monoclinic
_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
_cell_angle_alpha                90.00
_cell_angle_beta                 105.25(10)
_cell_angle_gamma                90.00
_cell_formula_units_Z            4
_cell_length_a                   4.009(10)
_cell_length_b                   14.59(3)
_cell_length_c                   11.59(3)
_cell_measurement_reflns_used    12419
_cell_measurement_temperature    293(2)
_cell_measurement_theta_max      24.93
_cell_measurement_theta_min      2.29
_cell_volume                     654(3)
_computing_cell_refinement       'DENZO (Otwinowski, 1988)'
_computing_data_collection       'MSC RAXIS11 Control software'
_computing_data_reduction        DENZO
_computing_publication_material
'TEXSAN (Molecular Structure Corporation, 1995)'
_computing_structure_refinement  'SHELXL97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS86 (Sheldrick, 1985)'
_diffrn_ambient_temperature      293(2)
_diffrn_measured_fraction_theta_full 0.732
_diffrn_measured_fraction_theta_max 0.732
_diffrn_measurement_device       'Rigaku R-AXIS'
_diffrn_measurement_method       '5 and 6\% \f'
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_source         'Rigaku rotating anode'
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71069
_diffrn_reflns_av_R_equivalents  0.05
_diffrn_reflns_av_sigmaI/netI    0.0336
_diffrn_reflns_limit_h_max       4
_diffrn_reflns_limit_h_min       0
_diffrn_reflns_limit_k_max       17
_diffrn_reflns_limit_k_min       0
_diffrn_reflns_limit_l_max       13
_diffrn_reflns_limit_l_min       -13
_diffrn_reflns_number            12419
_diffrn_reflns_theta_full        24.93
_diffrn_reflns_theta_max         24.93
_diffrn_reflns_theta_min         2.29
_diffrn_standards_decay_%        0.00
_diffrn_standards_interval_count 0
_diffrn_standards_number         0
_exptl_absorpt_coefficient_mu    0.089
_exptl_absorpt_correction_type   none
_exptl_crystal_colour            colourless
_exptl_crystal_density_diffrn    1.261
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       needle
_exptl_crystal_F_000             264
_exptl_crystal_size_max          0.6
_exptl_crystal_size_mid          0.1
_exptl_crystal_size_min          0.1
_refine_diff_density_max         0.176
_refine_diff_density_min         -0.153
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.099
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     88
_refine_ls_number_reflns         839
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.099
_refine_ls_R_factor_all          0.0503
_refine_ls_R_factor_gt           0.0408
_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^)+(0.0505P)^2^+0.2114P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1040
_refine_ls_wR_factor_ref         0.1102
_reflns_number_gt                724
_reflns_number_total             839
_reflns_threshold_expression     I>2\s(I)
_cod_data_source_file            at6083.cif
_cod_data_source_block           3c
_cod_original_sg_symbol_H-M      'P 21/n     '
_cod_database_code               2208241