Substituent effects on the regioselectivity of the Paternò-Büchi reaction of 5- or/and 6-methyl substituted uracils with 4,4'-disubstituted benzophenones.
Kong, Feng-Feng; Zhai, Bao-Chang; Song, Qin-Hua; Photochemical & photobiological sciences : Official journal of the European Photochemistry Association and the European Society for Photobiology 7 (2008) 1332–1336; doi:10.1039/b810640a

data_1516001
_publ_section_title
;
 Substituent effects on the regioselectivity of the Patern\`o-B\"uchi
 reaction of 5- or/and 6-methyl substituted uracils with
 4,4'-disubstituted benzophenones.
;
_journal_issue                   11
_journal_name_full
'Photochemical &amp; photobiological sciences : Official journal of the European Photochemistry Association and the European Society for Photobiology'
_journal_page_first              1332
_journal_page_last               1336
_journal_paper_doi               10.1039/b810640a
_journal_volume                  7
_journal_year                    2008
_chemical_formula_moiety         'C21 H22 N2 O3'
_chemical_formula_sum            'C21 H22 N2 O3'
_chemical_formula_weight         350.41
_chemical_name_common
;
(Z)-1,2,4,6-tetramethyl-8,8-diphenyl-7-oxa-2,4-diaza-bicyclo
(4.2.0)octane-3,5-dione
;
_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                 101.787(2)
_cell_angle_gamma                90.00
_cell_formula_units_Z            4
_cell_length_a                   16.102(2)
_cell_length_b                   10.7697(10)
_cell_length_c                   10.9403(12)
_cell_measurement_reflns_used    1679
_cell_measurement_temperature    298(2)
_cell_measurement_theta_max      19.857
_cell_measurement_theta_min      2.298
_cell_volume                     1857.2(4)
_computing_cell_refinement       'Bruker SMART'
_computing_data_collection       'Bruker SMART'
_computing_data_reduction        'Bruker SAINT'
_computing_molecular_graphics    'Bruker SHELXTL'
_computing_publication_material  'Bruker SHELXTL'
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 1990)'
_diffrn_ambient_temperature      298(2)
_diffrn_measured_fraction_theta_full 0.937
_diffrn_measured_fraction_theta_max 0.937
_diffrn_measurement_device_type  '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  0.1107
_diffrn_reflns_av_sigmaI/netI    0.2327
_diffrn_reflns_limit_h_max       19
_diffrn_reflns_limit_h_min       -18
_diffrn_reflns_limit_k_max       8
_diffrn_reflns_limit_k_min       -12
_diffrn_reflns_limit_l_max       12
_diffrn_reflns_limit_l_min       -13
_diffrn_reflns_number            8127
_diffrn_reflns_theta_full        25.01
_diffrn_reflns_theta_max         25.01
_diffrn_reflns_theta_min         2.29
_exptl_absorpt_coefficient_mu    0.084
_exptl_absorpt_correction_T_max  0.9964
_exptl_absorpt_correction_T_min  0.9670
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   sadabs
_exptl_crystal_colour            colorless
_exptl_crystal_density_diffrn    1.253
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       block
_exptl_crystal_F_000             744
_exptl_crystal_size_max          0.40
_exptl_crystal_size_mid          0.27
_exptl_crystal_size_min          0.04
_refine_diff_density_max         0.198
_refine_diff_density_min         -0.198
_refine_diff_density_rms         0.050
_refine_ls_extinction_coef       0.015(6)
_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   1.099
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     300
_refine_ls_number_reflns         3060
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.099
_refine_ls_R_factor_all          0.2085
_refine_ls_R_factor_gt           0.0948
_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^)+(0.0000P)^2^+1.3136P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.2317
_refine_ls_wR_factor_ref         0.3310
_reflns_number_gt                1244
_reflns_number_total             3060
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            b810640a.txt
_cod_data_source_block           3Dd
_cod_depositor_comments
;
The following automatic conversions were performed:

'_symmetry_cell_setting' value 'Monoclinic' changed to 'monoclinic'
according to
/usr/data/users/saulius/automatic-downloads/retrospective/RSC/lib/dictionaries/cif_core.dic
dictionary named 'cif_core.dic' version 2.4.2 from 2011-04-26.

Automatic conversion script
Id: cif_fix_values 2281 2013-09-26 08:29:07Z andrius 
;
_cod_original_sg_symbol_H-M      P2(1)/c
_cod_database_code               1516001