pTSA-catalyzed synthesis of functionalized chromeno[2,3-d]pyrimidine/chromeno[4,3-b]chromene derivatives via one-pot three component reaction: mechanistic insights and variable temperature NMR studies to investigate restricted bond rotation
Singh Tanwer, Yogesh Bhaskar; Sourabh, Suman; Bhunia, Sabyasachi; Pal, Sanchari; Das, Debjit; RSC Advances 15 (2025) 37090–37098; doi:10.1039/D5RA06198A

data_7250958
_publ_section_title
;
 pTSA-catalyzed synthesis of functionalized
 chromeno[2,3-d]pyrimidine/chromeno[4,3-b]chromene derivatives via one-pot
 three component reaction: mechanistic insights and variable temperature
 NMR studies to investigate restricted bond rotation
;
_journal_issue                   44
_journal_name_full               'RSC Advances'
_journal_page_first              37090
_journal_page_last               37098
_journal_paper_doi               10.1039/D5RA06198A
_journal_volume                  15
_journal_year                    2025
_chemical_formula_moiety         'C22 H21 Br N2 O6'
_chemical_formula_sum            'C22 H21 Br N2 O6'
_chemical_formula_weight         489.32
_space_group_crystal_system      triclinic
_space_group_IT_number           2
_space_group_name_Hall           '-P 1'
_space_group_name_H-M_alt        'P -1'
_atom_sites_solution_hydrogens   geom
_atom_sites_solution_primary     dual
_audit_creation_date             2023-08-24
_audit_creation_method
;
Olex2 1.2
(compiled 2018.05.29 svn.r3508 for OlexSys, GUI svn.r5506)
;
_audit_update_record
;
2025-04-06 deposited with the CCDC.	2025-09-29 downloaded from the CCDC.
;
_cell_angle_alpha                68.3900(10)
_cell_angle_beta                 73.5550(10)
_cell_angle_gamma                82.2480(10)
_cell_formula_units_Z            2
_cell_length_a                   7.8555(2)
_cell_length_b                   11.8073(3)
_cell_length_c                   12.6358(3)
_cell_measurement_reflns_used    970
_cell_measurement_temperature    100(2)
_cell_measurement_theta_max      33.662
_cell_measurement_theta_min      2.705
_cell_volume                     1044.43(5)
_computing_molecular_graphics    'Olex2 (Dolomanov et al., 2009)'
_computing_publication_material  'Olex2 (Dolomanov et al., 2009)'
_computing_structure_refinement  'ShelXL (Sheldrick, 2015)'
_computing_structure_solution    'ShelXT (Sheldrick, 2015)'
_diffrn_ambient_temperature      100.0
_diffrn_measured_fraction_theta_full 0.992
_diffrn_measured_fraction_theta_max 0.856
_diffrn_measurement_device_type  'Bruker APEX-II CCD'
_diffrn_measurement_method       '\f and \w scans'
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.0519
_diffrn_reflns_av_unetI/netI     0.0495
_diffrn_reflns_Laue_measured_fraction_full 0.992
_diffrn_reflns_Laue_measured_fraction_max 0.856
_diffrn_reflns_limit_h_max       11
_diffrn_reflns_limit_h_min       -12
_diffrn_reflns_limit_k_max       18
_diffrn_reflns_limit_k_min       -17
_diffrn_reflns_limit_l_max       15
_diffrn_reflns_limit_l_min       -19
_diffrn_reflns_number            33491
_diffrn_reflns_point_group_measured_fraction_full 0.992
_diffrn_reflns_point_group_measured_fraction_max 0.856
_diffrn_reflns_theta_full        25.242
_diffrn_reflns_theta_max         33.662
_diffrn_reflns_theta_min         2.705
_exptl_absorpt_coefficient_mu    2.011
_exptl_absorpt_correction_T_max  0.682
_exptl_absorpt_correction_T_min  0.623
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   'SADABAS 2.10 (Bruker 2003)'
_exptl_crystal_colour            pink
_exptl_crystal_density_diffrn    1.556
_exptl_crystal_description       block
_exptl_crystal_F_000             500
_exptl_crystal_size_max          0.24
_exptl_crystal_size_mid          0.22
_exptl_crystal_size_min          0.19
_refine_diff_density_max         1.808
_refine_diff_density_min         -1.854
_refine_diff_density_rms         0.129
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.037
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     285
_refine_ls_number_reflns         7114
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.037
_refine_ls_R_factor_all          0.0781
_refine_ls_R_factor_gt           0.0521
_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^)+(0.0771P)^2^+1.4883P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1377
_refine_ls_wR_factor_ref         0.1570
_reflns_Friedel_coverage         0.000
_reflns_number_gt                5387
_reflns_number_total             7114
_reflns_threshold_expression     'I > 2\s(I)'
_cod_data_source_file            d5ra06198a2.cif
_cod_data_source_block           mo_sv_c_04_0m
_cod_database_code               7250958
_shelx_shelxl_version_number     2018/1
_shelx_estimated_absorpt_t_max   0.682
_shelx_estimated_absorpt_t_min   0.623
_olex2_refinement_description
;
1. Fixed Uiso
 At 1.2 times of:
  All C(H) groups
 At 1.5 times of:
  All C(H,H,H) groups
2.a Ternary CH refined with riding coordinates:
 C10(H10)
2.b Aromatic/amide H refined with riding coordinates:
 C15(H15), C17(H17), C3(H3), C18(H18), C5(H5)
2.c Idealised Me refined as rotating group:
 C21(H21A,H21B,H21C), C8(H8A,H8B,H8C), C22(H22A,H22B,H22C), C9(H9A,H9B,H9C),
 C7(H7A,H7B,H7C)
;
_shelx_res_checksum              66963
_olex2_submission_special_instructions 'No special instructions were received'