Solvent-assisted one-pot green and diastereoselective synthesis of 1,4-oxazines and 1,4-thioxazines under metal-free conditions
Ahmad, Farukh; Singh, Rajeev; Ahmed, Naseem; Organic & Biomolecular Chemistry  (2026) –; doi:10.1039/D5OB01466B

data_7160912
_publ_section_title
;
 Solvent-assisted one-pot green and diastereoselective synthesis of
 1,4-oxazines and 1,4-thioxazines under metal-free conditions
;
_journal_name_full               'Organic &amp; Biomolecular Chemistry'
_journal_paper_doi               10.1039/D5OB01466B
_journal_year                    2026
_chemical_formula_moiety         'C24 H17 N O4'
_chemical_formula_sum            'C24 H17 N O4'
_chemical_formula_weight         383.38
_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   mixed
_audit_creation_method           SHELXL-2019/1
_audit_update_record
;
2025-09-02 deposited with the CCDC.	2025-11-26 downloaded from the CCDC.
;
_cell_angle_alpha                90
_cell_angle_beta                 146.592(5)
_cell_angle_gamma                90
_cell_formula_units_Z            4
_cell_length_a                   20.836(4)
_cell_length_b                   7.1335(13)
_cell_length_c                   21.837(5)
_cell_measurement_reflns_used    6533
_cell_measurement_temperature    300(2)
_cell_measurement_theta_max      19.6732
_cell_measurement_theta_min      3.0257
_cell_volume                     1787.1(7)
_computing_cell_refinement       'SAINT V8.40B (Bruker AXS LLC, 2019)'
_computing_data_collection
'Bruker APEX4 v2022.1-0'(Bruker AXS Inc., 2022)'
_computing_data_reduction        'SAINT V8.40B (Bruker AXS LLC, 2019)'
_computing_molecular_graphics    'shelXle (C.B. Huebschle, rev 1380)'
_computing_publication_material  'APEX4 v2022.1-0'(Bruker AXS Inc., 2022)'
_computing_structure_refinement  'SHELXL-2019/1 (Sheldrick, 2019)'
_computing_structure_solution    'XT, VERSION 2018/2'
_diffrn_ambient_temperature      300(2)
_diffrn_detector_area_resol_mean 7.3910
_diffrn_measured_fraction_theta_full 0.997
_diffrn_measured_fraction_theta_max 0.996
_diffrn_measurement_device_type  'Bruker D8 QUEST photon III C7'
_diffrn_measurement_method       '\ f and \ w scans'
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_unetI/netI     0.0347
_diffrn_reflns_Laue_measured_fraction_full 0.997
_diffrn_reflns_Laue_measured_fraction_max 0.996
_diffrn_reflns_limit_h_max       24
_diffrn_reflns_limit_h_min       0
_diffrn_reflns_limit_k_max       8
_diffrn_reflns_limit_k_min       0
_diffrn_reflns_limit_l_max       13
_diffrn_reflns_limit_l_min       -26
_diffrn_reflns_number            3218
_diffrn_reflns_point_group_measured_fraction_full 0.997
_diffrn_reflns_point_group_measured_fraction_max 0.996
_diffrn_reflns_theta_full        25.209
_diffrn_reflns_theta_max         25.209
_diffrn_reflns_theta_min         2.000
_diffrn_source                   'micro-focus sealed tube'
_exptl_absorpt_coefficient_mu    0.098
_exptl_absorpt_correction_T_max  0.99
_exptl_absorpt_correction_T_min  0.91
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details
;
Krause, L., Herbst-Irmer, R., Sheldrick, G. M., Stalke, D. (2015).
"Comparison of silver and molybdenum microfocus X-ray sources for
single-crystal structure determination"
J. Appl. Cryst. 48, 3-10.
doi:10.1107/S1600576714022985
;
_exptl_crystal_colour            'lusterous light yellow'
_exptl_crystal_density_diffrn    1.425
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       block
_exptl_crystal_F_000             800
_exptl_crystal_size_max          0.219
_exptl_crystal_size_mid          0.206
_exptl_crystal_size_min          0.089
_refine_diff_density_max         0.219
_refine_diff_density_min         -0.190
_refine_diff_density_rms         0.043
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.095
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     307
_refine_ls_number_reflns         3218
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.095
_refine_ls_R_factor_all          0.0824
_refine_ls_R_factor_gt           0.0618
_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^)+(0.0822P)^2^+1.0200P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1685
_refine_ls_wR_factor_ref         0.1864
_reflns_Friedel_coverage         0.000
_reflns_number_gt                2384
_reflns_number_total             3218
_reflns_threshold_expression     'I > 2\s(I)'
_cod_data_source_file            d5ob01466b2.cif
_cod_data_source_block           f
_cod_depositor_comments
;
The following automatic conversions were performed:

data item '_exptl_absorpt_correction_type' value 'Multi-Scan' was
changed to 'multi-scan' in accordance with the
/home/data/users/saulius/crontab/automatic-downloads/rss-feeds/RSC/lib/dictionaries/cif_core.dic
dictionary named 'cif_core.dic' version 2.4.2 last updated on
2011-04-26.

Automatic conversion script
Id: cif_fix_values 8170 2020-07-09 18:12:32Z antanas 
;
_cod_original_cell_volume        1787.1(6)
_cod_original_sg_symbol_H-M      'P 21/c'
_cod_database_code               7160912
_shelx_shelxl_version_number     2019/1
_shelx_estimated_absorpt_t_min   0.979
_shelx_estimated_absorpt_t_max   0.991
_shelx_res_checksum              12149