# Supplementary Information (SI) for Organic Chemistry Frontiers.
# This journal is © the Partner Organisations 2026

####################################################################### 
# 
# This file contains crystal structure data downloaded from the 
# Cambridge Structural Database (CSD) hosted by the Cambridge 
# Crystallographic Data Centre (CCDC).
# 
# Full information about CCDC data access policies and citation 
# guidelines are available at http://www.ccdc.cam.ac.uk/access/V1 
# 
# Audit and citation data items may have been added by the CCDC. 
# Please retain this information to preserve the provenance of 
# this file and to allow appropriate attribution of the data. 
# 
#######################################################################

data_37-mr-20251219a_auto
_audit_block_doi                 10.5517/ccdc.csd.cc2qj9rb
_database_code_depnum_ccdc_archive 'CCDC 2518122'
loop_
_audit_author_name
_audit_author_address
'Hong-Yu Zhang'
;Hebei University of Technology
China
;
_audit_update_record             
;
2025-12-22 deposited with the CCDC.	2025-12-29 downloaded from the CCDC.
;
_audit_creation_date             2025-12-19
_audit_creation_method           
;
Olex2 1.5-ac6-020
(compiled 2024.02.14 svn.r2f8d729c for Rigaku Oxford Diffraction, GUI svn.r6966)
;
_shelx_SHELXL_version_number     2018/3
_chemical_name_common            ?
_chemical_name_systematic        
'ethyl 2-(4-methyl-3,5-dioxo-4,5-dihydro-1,2,4-triazin-2(3H)-yl)acetate'
_chemical_formula_moiety         'C8 H11 N3 O4'
_chemical_formula_sum            'C8 H11 N3 O4'
_chemical_formula_weight         213.20
_chemical_melting_point          ?
loop_
_atom_type_symbol
_atom_type_description
_atom_type_scat_dispersion_real
_atom_type_scat_dispersion_imag
_atom_type_scat_source
C C 0.0033 0.0016 'International Tables Vol C Tables 4.2.6.8 and 6.1.1.4'
H H 0.0000 0.0000 'International Tables Vol C Tables 4.2.6.8 and 6.1.1.4'
N N 0.0061 0.0033 'International Tables Vol C Tables 4.2.6.8 and 6.1.1.4'
O O 0.0106 0.0060 'International Tables Vol C Tables 4.2.6.8 and 6.1.1.4'

_shelx_space_group_comment       
;
The symmetry employed for this shelxl refinement is uniquely defined
by the following loop, which should always be used as a source of
symmetry information in preference to the above space-group names.
They are only intended as comments.
;
_space_group_crystal_system      monoclinic
_space_group_IT_number           14
_space_group_name_H-M_alt        'P 1 21/c 1'
_space_group_name_Hall           '-P 2ybc'
loop_
_space_group_symop_operation_xyz
'x, y, z'
'-x, y+1/2, -z+1/2'
'-x, -y, -z'
'x, -y-1/2, z-1/2'

_cell_length_a                   15.3836(5)
_cell_length_b                   4.82420(10)
_cell_length_c                   13.9318(6)
_cell_angle_alpha                90
_cell_angle_beta                 111.195(4)
_cell_angle_gamma                90
_cell_volume                     963.99(6)
_cell_formula_units_Z            4
_cell_measurement_reflns_used    6280
_cell_measurement_temperature    100.01(10)
_cell_measurement_theta_max      33.5790
_cell_measurement_theta_min      2.8290
_shelx_estimated_absorpt_T_max   0.983
_shelx_estimated_absorpt_T_min   0.973
_exptl_absorpt_coefficient_mu    0.119
_exptl_absorpt_correction_T_max  1.00000
_exptl_absorpt_correction_T_min  0.95171
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   
;
CrysAlisPro 1.171.44.123a (Rigaku Oxford Diffraction, 2025)
Empirical absorption correction using spherical harmonics,
implemented in SCALE3 ABSPACK scaling algorithm.
;
_exptl_absorpt_special_details   ?
_exptl_crystal_colour            white
_exptl_crystal_density_diffrn    1.469
_exptl_crystal_density_meas      ?
_exptl_crystal_density_method    ?
_exptl_crystal_description       block
_exptl_crystal_F_000             448
_exptl_crystal_size_max          0.23
_exptl_crystal_size_mid          0.2
_exptl_crystal_size_min          0.14
_exptl_transmission_factor_max   ?
_exptl_transmission_factor_min   ?
_diffrn_reflns_av_R_equivalents  0.0192
_diffrn_reflns_av_unetI/netI     0.0174
_diffrn_reflns_Laue_measured_fraction_full 0.999
_diffrn_reflns_Laue_measured_fraction_max 0.999
_diffrn_reflns_limit_h_max       19
_diffrn_reflns_limit_h_min       -19
_diffrn_reflns_limit_k_max       6
_diffrn_reflns_limit_k_min       -6
_diffrn_reflns_limit_l_max       14
_diffrn_reflns_limit_l_min       -17
_diffrn_reflns_number            7256
_diffrn_reflns_point_group_measured_fraction_full 0.999
_diffrn_reflns_point_group_measured_fraction_max 0.999
_diffrn_reflns_theta_full        25.242
_diffrn_reflns_theta_max         26.370
_diffrn_reflns_theta_min         2.840
_diffrn_ambient_environment      N~2~
_diffrn_ambient_temperature      100.01(10)
_diffrn_detector                 'Hybrid Pixel Array Detector'
_diffrn_detector_area_resol_mean 10.0000
_diffrn_detector_type            'HyPix-Arc 150'
_diffrn_measured_fraction_theta_full 0.999
_diffrn_measured_fraction_theta_max 0.999
_diffrn_measurement_details      
;
List of Runs (angles in degrees, time in seconds):

  # Type    Start    End  Width  tₑₓₚ   ω     θ     κ     φ   Frames
#--------------------------------------------------------------------------
  1  ω     13.00  39.00   0.50    0.15    --   -0.39  64.00  83.61   52
  2  ω      9.00  34.00   0.50    0.15    --   -0.39  63.00  29.80   50
  3  ω    -54.00 -24.00   0.50    0.15    --   -0.39 -19.00 -90.00   60
  4  ω    -54.00 -23.00   0.50    0.15    --   -0.39 -19.00-150.00   62
  5  ω     25.00  53.00   0.50    0.15    --   -0.39  38.00 -90.00   56
  6  ω     15.00  42.00   0.50    0.15    --   -0.39  66.00 -99.05   54
  7  ω     16.00  43.00   0.50    0.15    --   -0.39  62.00 -37.04   54
  8  ω     17.00  43.00   0.50    0.15    --   -0.39  19.00  90.00   52
  9  ω     18.00  44.00   0.50    0.15    --   -0.39  19.00 150.00   52
;
_diffrn_measurement_device       'four-circle diffractometer'
_diffrn_measurement_device_type  'ROD, SynergyCustom DW system, HyPix-Arc 150'
_diffrn_measurement_method       'ω scans'
_diffrn_orient_matrix_type       
'CrysAlisPro convention (1999,Acta A55,543-557)'
_diffrn_orient_matrix_UB_11      -0.0348847000
_diffrn_orient_matrix_UB_12      0.0846791000
_diffrn_orient_matrix_UB_13      0.0070980000
_diffrn_orient_matrix_UB_21      -0.0316575000
_diffrn_orient_matrix_UB_22      -0.1128367000
_diffrn_orient_matrix_UB_23      -0.0138265000
_diffrn_orient_matrix_UB_31      0.0150129000
_diffrn_orient_matrix_UB_32      -0.0414577000
_diffrn_orient_matrix_UB_33      0.0523533000
_diffrn_oxdiff_digest_od_ed      
;

;
_diffrn_oxdiff_measurement_exp_name 37-MR-20251219A.par
_diffrn_radiation_monochromator  mirror
_diffrn_radiation_probe          x-ray
_diffrn_radiation_type           'Mo K\a'
_diffrn_radiation_wavelength     0.71073
_diffrn_source                   'Rotating-anode X-ray tube'
_diffrn_source_type              'Rigaku (Mo) X-ray Source'
_reflns_Friedel_coverage         0.000
_reflns_Friedel_fraction_full    .
_reflns_Friedel_fraction_max     .
_reflns_number_gt                1769
_reflns_number_total             1959
_reflns_special_details          
;
 Reflections were merged by SHELXL according to the crystal
 class for the calculation of statistics and refinement.
 
 _reflns_Friedel_fraction is defined as the number of unique
 Friedel pairs measured divided by the number that would be
 possible theoretically, ignoring centric projections and
 systematic absences.
;
_reflns_threshold_expression     'I > 2σ(I)'
_computing_cell_refinement       'CrysAlisPro 1.171.44.123a (Rigaku OD, 2025)'
_computing_data_collection       'CrysAlisPro 1.171.44.123a (Rigaku OD, 2025)'
_computing_data_reduction        'CrysAlisPro 1.171.44.123a (Rigaku OD, 2025)'
_computing_molecular_graphics    'Olex2 1.5-ac6-020 (Dolomanov et al., 2009)'
_computing_publication_material  'Olex2 1.5-ac6-020 (Dolomanov et al., 2009)'
_computing_structure_refinement  'SHELXL 2018/3 (Sheldrick, 2015)'
_computing_structure_solution    'SHELXT 2018/2 (Sheldrick, 2018)'
_refine_diff_density_max         0.217
_refine_diff_density_min         -0.196
_refine_diff_density_rms         0.041
_refine_ls_extinction_coef       .
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.059
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     138
_refine_ls_number_reflns         1959
_refine_ls_number_restraints     0
_refine_ls_R_factor_all          0.0324
_refine_ls_R_factor_gt           0.0295
_refine_ls_restrained_S_all      1.059
_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/[σ²(Fo²)+(0.0444P)²+0.2703P] where P=(Fo²+2Fc²)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0813
_refine_ls_wR_factor_ref         0.0835
_refine_special_details          ?
_olex2_refinement_description    
;
1. Fixed Uiso
 At 1.2 times of:
  All C(H) groups, All C(H,H) groups
 At 1.5 times of:
  All C(H,H,H) groups
2.a Secondary CH2 refined with riding coordinates:
 C2(H2A,H2B), C4(H4A,H4B)
2.b Aromatic/amide H refined with riding coordinates:
 C5(H5)
2.c Idealised Me refined as rotating group:
 C1(H1A,H1B,H1C), C8(H8A,H8B,H8C)
;
_atom_sites_solution_hydrogens   geom
_atom_sites_solution_primary     dual
_atom_sites_solution_secondary   ?
loop_
_atom_site_label
_atom_site_type_symbol
_atom_site_fract_x
_atom_site_fract_y
_atom_site_fract_z
_atom_site_U_iso_or_equiv
_atom_site_adp_type
_atom_site_occupancy
_atom_site_site_symmetry_order
_atom_site_calc_flag
_atom_site_refinement_flags_posn
_atom_site_refinement_flags_adp
_atom_site_refinement_flags_occupancy
_atom_site_disorder_assembly
_atom_site_disorder_group
O1 O 0.54396(5) 0.26065(15) 0.40929(6) 0.01734(18) Uani 1 1 d . . . . .
O3 O 0.75218(6) 0.13772(18) 0.28555(7) 0.0283(2) Uani 1 1 d . . . . .
O2 O 0.61456(5) 0.60490(16) 0.35604(6) 0.02163(19) Uani 1 1 d . . . . .
O4 O 0.96741(5) 0.83135(18) 0.37746(6) 0.0258(2) Uani 1 1 d . . . . .
N3 N 0.86521(6) 0.47162(19) 0.33081(7) 0.0171(2) Uani 1 1 d . . . . .
N1 N 0.78421(6) 0.35660(18) 0.43851(7) 0.0174(2) Uani 1 1 d . . . . .
N2 N 0.82706(6) 0.55849(19) 0.50753(7) 0.0182(2) Uani 1 1 d . . . . .
C3 C 0.61668(7) 0.3885(2) 0.39961(8) 0.0154(2) Uani 1 1 d . . . . .
C1 C 0.38297(7) 0.2191(2) 0.38323(9) 0.0203(2) Uani 1 1 d . . . . .
H1A H 0.378185 0.043902 0.346032 0.030 Uiso 1 1 calc R U . . .
H1B H 0.322249 0.312220 0.359001 0.030 Uiso 1 1 calc R U . . .
H1C H 0.402110 0.181624 0.457141 0.030 Uiso 1 1 calc R U . . .
C2 C 0.45420(7) 0.4026(2) 0.36404(8) 0.0169(2) Uani 1 1 d . . . . .
H2A H 0.438488 0.430141 0.289230 0.020 Uiso 1 1 calc R U . . .
H2B H 0.456415 0.585912 0.396776 0.020 Uiso 1 1 calc R U . . .
C5 C 0.88801(7) 0.7085(2) 0.48845(8) 0.0183(2) Uani 1 1 d . . . . .
H5 H 0.919823 0.845503 0.537585 0.022 Uiso 1 1 calc R U . . .
C4 C 0.70514(7) 0.2247(2) 0.45375(9) 0.0192(2) Uani 1 1 d . . . . .
H4A H 0.716539 0.214031 0.528288 0.023 Uiso 1 1 calc R U . . .
H4B H 0.697729 0.033529 0.426120 0.023 Uiso 1 1 calc R U . . .
C6 C 0.91158(7) 0.6823(2) 0.39619(8) 0.0172(2) Uani 1 1 d . . . . .
C7 C 0.79681(7) 0.3104(2) 0.34655(8) 0.0182(2) Uani 1 1 d . . . . .
C8 C 0.88480(8) 0.4283(3) 0.23635(9) 0.0250(3) Uani 1 1 d . . . . .
H8A H 0.850864 0.566187 0.184756 0.038 Uiso 1 1 calc R U . . .
H8B H 0.864744 0.241785 0.209594 0.038 Uiso 1 1 calc R U . . .
H8C H 0.951878 0.447933 0.251599 0.038 Uiso 1 1 calc R U . . .


_geom_special_details            
;
 All esds (except the esd in the dihedral angle between two l.s. planes)
 are estimated using the full covariance matrix.  The cell esds are taken
 into account individually in the estimation of esds in distances, angles
 and torsion angles; correlations between esds in cell parameters are only
 used when they are defined by crystal symmetry.  An approximate (isotropic)
 treatment of cell esds is used for estimating esds involving l.s. planes.
;
loop_
_geom_bond_atom_site_label_1
_geom_bond_atom_site_label_2
_geom_bond_distance
_geom_bond_site_symmetry_2
_geom_bond_publ_flag
O1 C3 1.3264(12) . ?
O1 C2 1.4641(12) . ?
O3 C7 1.2108(14) . ?
O2 C3 1.2019(13) . ?
O4 C6 1.2184(13) . ?
N3 C6 1.3792(14) . ?
N3 C7 1.3880(13) . ?
N3 C8 1.4675(13) . ?
N1 N2 1.3599(12) . ?
N1 C4 1.4548(12) . ?
N1 C7 1.3813(14) . ?
N2 C5 1.2860(14) . ?
C3 C4 1.5175(14) . ?
C1 H1A 0.9800 . ?
C1 H1B 0.9800 . ?
C1 H1C 0.9800 . ?
C1 C2 1.5060(14) . ?
C2 H2A 0.9900 . ?
C2 H2B 0.9900 . ?
C5 H5 0.9500 . ?
C5 C6 1.4618(15) . ?
C4 H4A 0.9900 . ?
C4 H4B 0.9900 . ?
C8 H8A 0.9800 . ?
C8 H8B 0.9800 . ?
C8 H8C 0.9800 . ?

loop_
_geom_angle_atom_site_label_1
_geom_angle_atom_site_label_2
_geom_angle_atom_site_label_3
_geom_angle
_geom_angle_site_symmetry_1
_geom_angle_site_symmetry_3
_geom_angle_publ_flag
C3 O1 C2 115.94(8) . . ?
C6 N3 C7 123.32(9) . . ?
C6 N3 C8 118.19(9) . . ?
C7 N3 C8 118.37(9) . . ?
N2 N1 C4 115.29(8) . . ?
N2 N1 C7 125.21(9) . . ?
C7 N1 C4 118.03(9) . . ?
C5 N2 N1 117.40(9) . . ?
O1 C3 C4 110.17(8) . . ?
O2 C3 O1 125.83(10) . . ?
O2 C3 C4 123.99(9) . . ?
H1A C1 H1B 109.5 . . ?
H1A C1 H1C 109.5 . . ?
H1B C1 H1C 109.5 . . ?
C2 C1 H1A 109.5 . . ?
C2 C1 H1B 109.5 . . ?
C2 C1 H1C 109.5 . . ?
O1 C2 C1 106.39(8) . . ?
O1 C2 H2A 110.5 . . ?
O1 C2 H2B 110.5 . . ?
C1 C2 H2A 110.5 . . ?
C1 C2 H2B 110.5 . . ?
H2A C2 H2B 108.6 . . ?
N2 C5 H5 117.8 . . ?
N2 C5 C6 124.35(10) . . ?
C6 C5 H5 117.8 . . ?
N1 C4 C3 110.27(8) . . ?
N1 C4 H4A 109.6 . . ?
N1 C4 H4B 109.6 . . ?
C3 C4 H4A 109.6 . . ?
C3 C4 H4B 109.6 . . ?
H4A C4 H4B 108.1 . . ?
O4 C6 N3 122.00(10) . . ?
O4 C6 C5 123.75(10) . . ?
N3 C6 C5 114.26(9) . . ?
O3 C7 N3 122.99(10) . . ?
O3 C7 N1 121.86(10) . . ?
N1 C7 N3 115.14(9) . . ?
N3 C8 H8A 109.5 . . ?
N3 C8 H8B 109.5 . . ?
N3 C8 H8C 109.5 . . ?
H8A C8 H8B 109.5 . . ?
H8A C8 H8C 109.5 . . ?
H8B C8 H8C 109.5 . . ?

loop_
_geom_torsion_atom_site_label_1
_geom_torsion_atom_site_label_2
_geom_torsion_atom_site_label_3
_geom_torsion_atom_site_label_4
_geom_torsion
_geom_torsion_site_symmetry_1
_geom_torsion_site_symmetry_2
_geom_torsion_site_symmetry_3
_geom_torsion_site_symmetry_4
_geom_torsion_publ_flag
O1 C3 C4 N1 176.92(8) . . . . ?
O2 C3 C4 N1 -4.16(15) . . . . ?
N1 N2 C5 C6 2.23(15) . . . . ?
N2 N1 C4 C3 86.54(11) . . . . ?
N2 N1 C7 O3 -175.39(10) . . . . ?
N2 N1 C7 N3 5.89(15) . . . . ?
N2 C5 C6 O4 177.67(11) . . . . ?
N2 C5 C6 N3 -2.53(15) . . . . ?
C3 O1 C2 C1 179.33(8) . . . . ?
C2 O1 C3 O2 -1.31(15) . . . . ?
C2 O1 C3 C4 177.59(8) . . . . ?
C4 N1 N2 C5 -169.91(9) . . . . ?
C4 N1 C7 O3 -9.92(15) . . . . ?
C4 N1 C7 N3 171.36(9) . . . . ?
C6 N3 C7 O3 175.13(10) . . . . ?
C6 N3 C7 N1 -6.17(15) . . . . ?
C7 N3 C6 O4 -175.61(10) . . . . ?
C7 N3 C6 C5 4.59(14) . . . . ?
C7 N1 N2 C5 -4.08(15) . . . . ?
C7 N1 C4 C3 -80.37(12) . . . . ?
C8 N3 C6 O4 0.16(15) . . . . ?
C8 N3 C6 C5 -179.64(9) . . . . ?
C8 N3 C7 O3 -0.64(16) . . . . ?
C8 N3 C7 N1 178.07(9) . . . . ?

_olex2_submission_special_instructions 'No special instructions were received'
_oxdiff_exptl_absorpt_empirical_details 
;
Empirical correction (ABSPACK) includes:
- Absorption correction using spherical harmonics
- Frame scaling
;
_oxdiff_exptl_absorpt_empirical_full_max 1.212
_oxdiff_exptl_absorpt_empirical_full_min 0.902
