Regioselective cyclocondensations with thiobarbituric acid: spirocyclic and azocine products, X-ray characterization, and antioxidant evaluation
Polo-Cuadrado, Efraín; Acosta-Quiroga, Karen; Rojas-Peña, Cristian; Rodriguez-Nuñez, Yeray A.; Blanco-Acuña, Edgard Fabián; Lopez, Jhon J.; Brito, Iván; Cisterna, Jonathan; Alderete, Joel B.; Gutiérrez, Margarita; RSC Advances 15 (2025) 8609–8621; doi:10.1039/D4RA07966C

data_7250131
_publ_section_title
;
 Regioselective cyclocondensations with thiobarbituric acid: spirocyclic
 and azocine products, X-ray characterization, and antioxidant evaluation
;
_journal_issue                   11
_journal_name_full               'RSC Advances'
_journal_page_first              8609
_journal_page_last               8621
_journal_paper_doi               10.1039/D4RA07966C
_journal_volume                  15
_journal_year                    2025
_chemical_formula_moiety         'C19 H21 N5 O3 S'
_chemical_formula_sum            'C19 H21 N5 O3 S'
_chemical_formula_weight         399.47
_space_group_crystal_system      monoclinic
_space_group_IT_number           14
_space_group_name_Hall           '-P 2ybc'
_space_group_name_H-M_alt        'P 1 21/c 1'
_atom_sites_solution_hydrogens   geom
_audit_creation_date             2022-08-11
_audit_creation_method
;
Olex2 1.3
(compiled 2020.11.12 svn.r5f609507 for OlexSys, GUI svn.r6408)
;
_audit_update_record
;
2022-08-11 deposited with the CCDC.	2025-02-12 downloaded from the CCDC.
;
_cell_angle_alpha                90
_cell_angle_beta                 102.261(2)
_cell_angle_gamma                90
_cell_formula_units_Z            4
_cell_length_a                   8.6243(6)
_cell_length_b                   20.6113(13)
_cell_length_c                   10.7734(7)
_cell_measurement_temperature    297.75
_cell_volume                     1871.4(2)
_computing_molecular_graphics    'Olex2 1.3 (Dolomanov et al., 2009)'
_computing_publication_material  'Olex2 1.3 (Dolomanov et al., 2009)'
_computing_structure_refinement  'XL  (Sheldrick, 2008)'
_computing_structure_solution    'SHELXT 2018/2 (Sheldrick, 2018)'
_diffrn_ambient_temperature      297.75
_diffrn_measured_fraction_theta_full 0.997
_diffrn_measured_fraction_theta_max 0.995
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.0372
_diffrn_reflns_av_unetI/netI     0.0265
_diffrn_reflns_Laue_measured_fraction_full 0.997
_diffrn_reflns_Laue_measured_fraction_max 0.995
_diffrn_reflns_limit_h_max       11
_diffrn_reflns_limit_h_min       -11
_diffrn_reflns_limit_k_max       27
_diffrn_reflns_limit_k_min       -26
_diffrn_reflns_limit_l_max       14
_diffrn_reflns_limit_l_min       -14
_diffrn_reflns_number            22466
_diffrn_reflns_point_group_measured_fraction_full 0.997
_diffrn_reflns_point_group_measured_fraction_max 0.995
_diffrn_reflns_theta_full        25.242
_diffrn_reflns_theta_max         28.380
_diffrn_reflns_theta_min         3.543
_exptl_absorpt_coefficient_mu    0.205
_exptl_crystal_density_diffrn    1.418
_exptl_crystal_F_000             840
_exptl_crystal_size_max          0.19
_exptl_crystal_size_mid          0.17
_exptl_crystal_size_min          0.02
_refine_diff_density_max         0.416
_refine_diff_density_min         -0.345
_refine_diff_density_rms         0.049
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.058
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     255
_refine_ls_number_reflns         4675
_refine_ls_number_restraints     3
_refine_ls_restrained_S_all      1.064
_refine_ls_R_factor_all          0.0566
_refine_ls_R_factor_gt           0.0438
_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^)+(0.0482P)^2^+1.1866P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1104
_refine_ls_wR_factor_ref         0.1192
_reflns_Friedel_coverage         0.000
_reflns_number_gt                3814
_reflns_number_total             4675
_reflns_threshold_expression     'I > 2\s(I)'
_cod_data_source_file            d4ra07966c2.cif
_cod_data_source_block           mg_e42021_00
_cod_database_code               7250131
_shelx_shelxl_version_number     2018/3
_shelx_estimated_absorpt_t_max   0.996
_shelx_estimated_absorpt_t_min   0.962
_olex2_refinement_description
;
1. Fixed Uiso
 At 1.2 times of:
  All C(H) groups, All C(H,H) groups, All N(H,H) groups
 At 1.5 times of:
  All C(H,H,H) groups
2. Restrained distances
 N2-C1 \\sim N2-C3 \\sim N2-C19
 with sigma of 0.02
3.a Secondary CH2 refined with riding coordinates:
 C3(H3A,H3B), C14(H14A,H14B), C17(H17A,H17B), C20(H20A,H20B)
3.b Aromatic/amide H refined with riding coordinates:
 C6(H6), C7(H7), C8(H8), C9(H9), C10(H10)
3.c X=CH2 refined with riding coordinates:
 N1(H1A,H1B)
3.d Idealised Me refined as rotating group:
 C12(H12A,H12B,H12C), C18(H18A,H18B,H18C)
;
_shelx_res_checksum              39190
_shelx_hkl_checksum              30839
_olex2_submission_special_instructions 'No special instructions were received'