Ketenes as dienophiles in aza-Diels-Alder reactions with dicyanohydrazones for accessing pyridazin-3(2<i>H</i>)-ones.
Zhu, Chen; Zhang, Jing; Yang, Jiaxin; Li, Xinxin; Wang, Xinyu; Shi, Hu; Jin, Hui; Zhang, Lixin; Organic & biomolecular chemistry 23 (2025) 6220–6224; doi:10.1039/d5ob00844a

data_7160580
_publ_section_title
;
 Ketenes as dienophiles in aza-Diels-Alder reactions with
 dicyanohydrazones for accessing pyridazin-3(2<i>H</i>)-ones.
;
_journal_issue                   25
_journal_name_full               'Organic &amp; biomolecular chemistry'
_journal_page_first              6220
_journal_page_last               6224
_journal_paper_doi               10.1039/d5ob00844a
_journal_volume                  23
_journal_year                    2025
_chemical_formula_sum            'C15 H16 N4 O'
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_space_group_crystal_system      orthorhombic
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_space_group_name_Hall           '-P 2ac 2ab'
_space_group_name_H-M_alt        'P b c a'
_atom_sites_solution_hydrogens   geom
_audit_creation_method           SHELXL-2014/7
_audit_update_record
;
2024-08-27 deposited with the CCDC.	2025-05-28 downloaded from the CCDC.
;
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_cell_volume                     2946.7(5)
_computing_structure_refinement  'SHELXL-2014/7 (Sheldrick, 2014)'
_diffrn_ambient_temperature      296(2)
_diffrn_measured_fraction_theta_full 0.998
_diffrn_measured_fraction_theta_max 0.998
_diffrn_measurement_device_type  CCD
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.1179
_diffrn_reflns_av_unetI/netI     0.0474
_diffrn_reflns_Laue_measured_fraction_full 0.998
_diffrn_reflns_Laue_measured_fraction_max 0.998
_diffrn_reflns_limit_h_max       13
_diffrn_reflns_limit_h_min       -13
_diffrn_reflns_limit_k_max       13
_diffrn_reflns_limit_k_min       -13
_diffrn_reflns_limit_l_max       26
_diffrn_reflns_limit_l_min       -26
_diffrn_reflns_number            52590
_diffrn_reflns_point_group_measured_fraction_full 0.998
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_diffrn_reflns_theta_full        25.101
_diffrn_reflns_theta_max         25.101
_diffrn_reflns_theta_min         2.536
_exptl_absorpt_coefficient_mu    0.080
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   sadabs
_exptl_crystal_colour            colorless
_exptl_crystal_density_diffrn    1.210
_exptl_crystal_description       block
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_exptl_crystal_size_max          0.200
_exptl_crystal_size_mid          0.200
_exptl_crystal_size_min          0.200
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_exptl_transmission_factor_min   0.864
_refine_diff_density_max         0.183
_refine_diff_density_min         -0.211
_refine_diff_density_rms         0.046
_refine_ls_extinction_method     none
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_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     184
_refine_ls_number_reflns         2620
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.158
_refine_ls_R_factor_all          0.1454
_refine_ls_R_factor_gt           0.0921
_refine_ls_shift/su_max          0.000
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'w=1/[\s^2^(Fo^2^)+(0.0840P)^2^+2.6141P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1930
_refine_ls_wR_factor_ref         0.2229
_reflns_Friedel_coverage         0.000
_reflns_number_gt                1718
_reflns_number_total             2620
_reflns_threshold_expression     'I > 2\s(I)'
_cod_data_source_file            d5ob00844a2.cif
_cod_data_source_block           1_a
_cod_depositor_comments          'Adding full bibliography for 7160580.cif.'
_cod_database_code               7160580
_shelx_shelxl_version_number     2014/7
_shelx_estimated_absorpt_t_min   0.984
_shelx_estimated_absorpt_t_max   0.984
_shelx_res_checksum              75264