Controlled stepwise conversion of 2,4,6,8-tetrachloropyrimido[5,4-d]pyrimidine into 2,4,6,8-tetrasubstituted pyrimido[5,4-d]pyrimidines
Julian S. Northen; F. Thomas Boyle; William Clegg; Nicola J. Curtin; Andrew J. Edwards; Roger J. Griffin; Bernard T. Golding; J. Chem. Soc., Perkin Trans. 1  (2002) 108–115; doi:10.1039/b102224p

data_7204144
_publ_section_title
;
 Controlled stepwise conversion of
 2,4,6,8-tetrachloropyrimido[5,4-d]pyrimidine into
 2,4,6,8-tetrasubstituted pyrimido[5,4-d]pyrimidines
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_journal_issue                   1
_journal_name_full               'J. Chem. Soc., Perkin Trans. 1'
_journal_page_first              108
_journal_page_last               115
_journal_paper_doi               10.1039/b102224p
_journal_year                    2002
_chemical_formula_sum            'C16 H19 N7 O'
_chemical_formula_weight         325.38
_space_group_IT_number           60
_symmetry_cell_setting           orthorhombic
_symmetry_space_group_name_Hall  '-P 2n 2ab'
_symmetry_space_group_name_H-M   'P b c n'
_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                   38.754(8)
_cell_length_b                   7.9580(16)
_cell_length_c                   20.954(4)
_cell_measurement_reflns_used    63
_cell_measurement_temperature    160(2)
_cell_measurement_theta_max      27.0
_cell_measurement_theta_min      2.0
_cell_volume                     6462(2)
_computing_cell_refinement       'Siemens SMART'
_computing_data_collection       'Siemens SMART'
_computing_data_reduction        'Siemens SAINT'
_computing_molecular_graphics    'Siemens SHELXTL'
_computing_publication_material  'SHELXTL and local programs'
_computing_structure_refinement  'Siemens SHELXTL'
_computing_structure_solution    'Siemens SHELXTL'
_diffrn_ambient_temperature      160(2)
_diffrn_measured_fraction_theta_full 0.768
_diffrn_measured_fraction_theta_max 0.768
_diffrn_measurement_device_type  'Siemens SMART CCD diffractometer'
_diffrn_measurement_method       '\w rotation with narrow frames'
_diffrn_radiation_monochromator  'silicon 111'
_diffrn_radiation_source         'Daresbury SRS station 9.8'
_diffrn_radiation_type           synchrotron
_diffrn_radiation_wavelength     0.6889
_diffrn_reflns_av_R_equivalents  0.0678
_diffrn_reflns_av_sigmaI/netI    0.0966
_diffrn_reflns_limit_h_max       51
_diffrn_reflns_limit_h_min       -15
_diffrn_reflns_limit_k_max       10
_diffrn_reflns_limit_k_min       -8
_diffrn_reflns_limit_l_max       25
_diffrn_reflns_limit_l_min       -21
_diffrn_reflns_number            15409
_diffrn_reflns_theta_full        27.03
_diffrn_reflns_theta_max         27.03
_diffrn_reflns_theta_min         1.95
_diffrn_standards_decay_%        15
_diffrn_standards_number         0
_exptl_absorpt_coefficient_mu    0.091
_exptl_absorpt_correction_type   none
_exptl_crystal_colour            colourless
_exptl_crystal_density_diffrn    1.338
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       needle
_exptl_crystal_F_000             2752
_exptl_crystal_size_max          0.30
_exptl_crystal_size_mid          0.10
_exptl_crystal_size_min          0.10
_refine_diff_density_max         0.710
_refine_diff_density_min         -0.261
_refine_diff_density_rms         0.071
_refine_ls_extinction_coef       0.0027(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   0.893
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     460
_refine_ls_number_reflns         6638
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      0.893
_refine_ls_R_factor_all          0.1088
_refine_ls_R_factor_gt           0.0558
_refine_ls_shift/su_max          0.001
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'w=1/[\s^2^(Fo^2^)+(0.0666P)^2^+0.0000P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1206
_refine_ls_wR_factor_ref         0.1386
_reflns_number_gt                3737
_reflns_number_total             6638
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            b102224p.txt
_cod_data_source_block           nuc7
_cod_depositor_comments
;
The following automatic conversions were performed:

'_refine_ls_weighting_scheme' value 'calc
w=1/[\s^2^(Fo^2^)+(0.0666P)^2^+0.0000P] where P=(Fo^2^+2Fc^2^)/3' was
changed to 'calc'. New tag '_refine_ls_weighting_details' was
created. The value of the new tag was set to
'w=1/[\s^2^(Fo^2^)+(0.0666P)^2^+0.0000P] where P=(Fo^2^+2Fc^2^)/3'.

Automatic conversion script
Id: cif_fix_values 3143 2015-03-26 13:38:13Z robertas 
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_cod_original_sg_symbol_H-M      Pbcn
_cod_database_code               7204144