Potassium Hydrogen Sulfate Promoted One-pot Synthesis of Bis(indolyl)alkane Esters from α-Keto Carboxylic Acids: In Silico and In Vitro Anticancer Studies
Ballanki, Trinadh; Subramanian, Anjali Devi; Chinnappa, Pravin; Suresh Kumar, Vaishnu; Garg, Mohit; Jebiti, Haribabu; Moraga, Daniel; Viswambharan, Baby; Organic & Biomolecular Chemistry  (2025) –; doi:10.1039/D6OB00318D

data_7161096
_publ_section_title
;
 Potassium hydrogen sulfate promoted one-pot synthesis of
 bis(indolyl)alkane esters from &#x3b1;-keto carboxylic acids: <i>in
 silico</i> and <i>in vitro</i> anticancer studies.
;
_journal_issue                   17
_journal_name_full               'Organic &amp; biomolecular chemistry'
_journal_page_first              3737
_journal_page_last               3747
_journal_paper_doi               10.1039/d6ob00318d
_journal_volume                  24
_journal_year                    2026
_chemical_formula_moiety         'C25 H24 N2 O2'
_chemical_formula_sum            'C25 H24 N2 O2'
_chemical_formula_weight         384.46
_space_group_crystal_system      monoclinic
_space_group_IT_number           14
_space_group_name_Hall           '-P 2yn'
_space_group_name_H-M_alt        'P 1 21/n 1'
_atom_sites_solution_hydrogens   geom
_audit_block_doi                 10.5517/ccdc.csd.cc2m7vlb
_audit_creation_date             2024-12-08
_audit_creation_method
;
Olex2 1.5
(compiled 2024.02.16 svn.r378c4104 for OlexSys, GUI svn.r6928)
;
_audit_update_record
;
2025-01-30 deposited with the CCDC.	2026-03-30 downloaded from the CCDC.
;
_cell_angle_alpha                90
_cell_angle_beta                 109.097(6)
_cell_angle_gamma                90
_cell_formula_units_Z            4
_cell_length_a                   10.933(2)
_cell_length_b                   12.500(2)
_cell_length_c                   15.856(3)
_cell_measurement_reflns_used    9756
_cell_measurement_temperature    300(2)
_cell_measurement_theta_max      27.88
_cell_measurement_theta_min      2.56
_cell_volume                     2047.7(6)
_computing_cell_refinement       'Bruker APEX4/SAINT'
_computing_data_collection       'Bruker APEX4'
_computing_data_reduction        'Bruker APEX4/SAINT'
_computing_molecular_graphics    'Olex2 1.5 (Dolomanov et al., 2009)'
_computing_publication_material  'Olex2 1.5 (Dolomanov et al., 2009)'
_computing_structure_refinement  'SHELXL 2019/3 (Sheldrick, 2015)'
_computing_structure_solution    'SHELXT 2018/2 (Sheldrick, 2018)'
_diffrn_ambient_temperature      300.00
_diffrn_measured_fraction_theta_full 0.996
_diffrn_measured_fraction_theta_max 0.996
_diffrn_measurement_device_type
'Bruker D8 QUEST diffractometer with PHOTON II detector'
_diffrn_measurement_method       '\f and \w scans'
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.0411
_diffrn_reflns_av_unetI/netI     0.0226
_diffrn_reflns_Laue_measured_fraction_full 0.996
_diffrn_reflns_Laue_measured_fraction_max 0.996
_diffrn_reflns_limit_h_max       14
_diffrn_reflns_limit_h_min       -14
_diffrn_reflns_limit_k_max       16
_diffrn_reflns_limit_k_min       -16
_diffrn_reflns_limit_l_max       21
_diffrn_reflns_limit_l_min       -21
_diffrn_reflns_number            57573
_diffrn_reflns_point_group_measured_fraction_full 0.996
_diffrn_reflns_point_group_measured_fraction_max 0.996
_diffrn_reflns_theta_full        25.242
_diffrn_reflns_theta_max         28.282
_diffrn_reflns_theta_min         2.558
_diffrn_source                   'i-mu-s microfocus source'
_exptl_absorpt_coefficient_mu    0.079
_exptl_absorpt_correction_T_max  0.7457
_exptl_absorpt_correction_T_min  0.6905
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   'SADABS (BRUKER)'
_exptl_crystal_colour            brown
_exptl_crystal_density_diffrn    1.247
_exptl_crystal_description       block
_exptl_crystal_F_000             816
_exptl_crystal_size_max          0.37
_exptl_crystal_size_mid          0.223
_exptl_crystal_size_min          0.185
_refine_diff_density_max         0.370
_refine_diff_density_min         -0.255
_refine_diff_density_rms         0.036
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.041
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     310
_refine_ls_number_reflns         5061
_refine_ls_number_restraints     36
_refine_ls_restrained_S_all      1.057
_refine_ls_R_factor_all          0.0757
_refine_ls_R_factor_gt           0.0607
_refine_ls_shift/su_max          0.001
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'w=1/[\s^2^(Fo^2^)+(0.0635P)^2^+0.8114P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1464
_refine_ls_wR_factor_ref         0.1576
_reflns_Friedel_coverage         0.000
_reflns_number_gt                4063
_reflns_number_total             5061
_reflns_threshold_expression     'I > 2\s(I)'
_cod_data_source_file            d6ob00318d2.cif
_cod_data_source_block           cp_111_96_181024_0m_a
_cod_depositor_comments          'Adding full bibliography for 7161096.cif.'
_cod_original_cell_volume        2047.7(7)
_cod_database_code               7161096
_shelx_shelxl_version_number     2019/3
_shelx_estimated_absorpt_t_max   0.985
_shelx_estimated_absorpt_t_min   0.971
_olex2_refinement_description
;
1. Fixed Uiso
 At 1.2 times of:
  All C(H) groups, All C(H,H) groups, All C(H,H,H,H) groups
 At 1.5 times of:
  All C(H,H,H) groups
2. Restrained distances
 N1-C4 \\sim N1-C4A
 with sigma of 0.02
 C4-C17 \\sim C4A-C17A
 with sigma of 0.02
 C17-C18 \\sim C17A-C18A
 with sigma of 0.02
 N1-C17 \\sim N1-C17A
 with sigma of 0.04
 C4-C18 \\sim C4A-C18A
 with sigma of 0.04
3. Rigid bond restraints
 C17, C18
 with sigma for 1-2 distances of 0.002 and sigma for 1-3 distances of 0.002
4. Uiso/Uaniso restraints and constraints
C17 \\sim C18A: within 2A with sigma of 0.002 and sigma for terminal atoms of
0.004 within 2A
N1 \\sim C4A: within 2A with sigma of 0.002 and sigma for terminal atoms of
0.004 within 2A
C20 \\sim C21B: within 2A with sigma of 0.002 and sigma for terminal atoms of
0.004 within 2A
C21A \\sim C22A: within 2A with sigma of 0.002 and sigma for terminal atoms of
0.004 within 2A
C21B \\sim C22B: within 2A with sigma of 0.002 and sigma for terminal atoms of
0.004 within 2A
5. Others
 Sof(C4A)=Sof(H4AA)=Sof(H4AB)=Sof(C17A)=Sof(H17A)=Sof(C18A)=Sof(H18C)=
 Sof(H18D)=1-FVAR(1)
 Sof(C4)=Sof(H4A)=Sof(H4B)=Sof(C17)=Sof(H17)=Sof(C18)=Sof(H18A)=Sof(H18B)=
 FVAR(1)
 Sof(H20C)=Sof(H20D)=Sof(C21B)=Sof(H21B)=Sof(C22B)=Sof(H22C)=Sof(H22D)=1-FVAR(2)
 Sof(H20A)=Sof(H20B)=Sof(C21A)=Sof(H21A)=Sof(C22A)=Sof(H22A)=Sof(H22B)=FVAR(2)
6.a Ternary CH refined with riding coordinates:
 C12(H12)
6.b Secondary CH2 refined with riding coordinates:
 C4(H4A,H4B), C4A(H4AA,H4AB), C20(H20C,H20D), C20(H20A,H20B)
6.c Aromatic/amide H refined with riding coordinates:
 C1(H1), C3(H3), C7(H7), C8(H8), C9(H9), C10(H10), C14(H14), C17(H17),
 C17A(H17A), C21A(H21A), C21B(H21B), C23(H23), C24(H24), C25(H25)
6.d X=CH2 refined with riding coordinates:
 C18(H18A,H18B), C18A(H18C,H18D), C22A(H22A,H22B), C22B(H22C,H22D)
6.e Idealised Me refined as rotating group:
 C19(H19A,H19B,H19C)
;
_shelx_res_checksum              11762
_olex2_submission_special_instructions 'No special instructions were received'