PIDA-Mediated 1,2-ipso-Migration in Mannich Bases of Imidazo[1,2-a]pyridines: Preparation of N-Acetoxymethyl/ Alkoxymethyl-N-arylimidazo[1,2-a]pyridine-3-amines.
Patel, Om P. S.; Jaspal, Sonam; Shinde, Vikki N.; Nandwana, Nitesh Kumar; Rangan, Krishnan; Kumar, Anil; The Journal of organic chemistry  (2020) –; doi:10.1021/acs.joc.0c00674

data_4038424
_publ_section_title
;
 PIDA-Mediated 1,2-ipso-Migration in Mannich Bases of
 Imidazo[1,2-a]pyridines: Preparation of N-Acetoxymethyl/
 Alkoxymethyl-N-arylimidazo[1,2-a]pyridine-3-amines.
;
_journal_name_full               'The Journal of organic chemistry'
_journal_paper_doi               10.1021/acs.joc.0c00674
_journal_year                    2020
_chemical_formula_moiety         'C21 H18 N4 O2'
_chemical_formula_sum            'C21 H18 N4 O2'
_chemical_formula_weight         358.39
_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
_atom_sites_solution_primary     dual
_audit_creation_date             2019-02-18
_audit_creation_method
;
Olex2 1.2
(compiled 2018.05.29 svn.r3508 for OlexSys, GUI svn.r5506)
;
_cell_angle_alpha                90
_cell_angle_beta                 93.418(3)
_cell_angle_gamma                90
_cell_formula_units_Z            4
_cell_length_a                   9.0770(3)
_cell_length_b                   17.0044(6)
_cell_length_c                   11.4160(3)
_cell_measurement_reflns_used    13001
_cell_measurement_temperature    93(2)
_cell_measurement_theta_max      31.4110
_cell_measurement_theta_min      3.6520
_cell_volume                     1758.91(10)
_computing_cell_refinement       'CrysAlisPro 1.171.39.20a (Rigaku OD, 2015)'
_computing_data_collection       'CrysAlisPro 1.171.39.20a (Rigaku OD, 2015)'
_computing_data_reduction        'CrysAlisPro 1.171.39.20a (Rigaku OD, 2015)'
_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      93(2)
_diffrn_detector                 'CCD plate'
_diffrn_measured_fraction_theta_full 0.997
_diffrn_measured_fraction_theta_max 0.886
_diffrn_measurement_details
;
List of Runs (angles in degrees, time in seconds):

  # Type    Start    End  Width  t~exp~   \w     \q     \k     \f   Frames
--------------------------------------------------------------------------
  1  \w    -20.00  92.00   0.50   29.00    --    3.60  19.00 150.00  224
  2  \w    -15.00  65.00   0.50   29.00    --    3.60  37.00 -30.00  160
  3  \w    -77.00 -50.00   0.50   29.00    --    3.60 -19.00  30.00   54
  4  \w    -19.00  63.00   0.50   29.00    --    3.60  57.00  60.00  164
;
_diffrn_measurement_device       'four-circle diffractometer'
_diffrn_measurement_device_type  'XtaLAB Pro: Kappa dual offset/far'
_diffrn_measurement_method       '\w scans'
_diffrn_orient_matrix_type
'CrysAlisPro convention (1999,Acta A55,543-557)'
_diffrn_orient_matrix_UB_11      0.0388866000
_diffrn_orient_matrix_UB_12      0.0352419000
_diffrn_orient_matrix_UB_13      -0.0104823000
_diffrn_orient_matrix_UB_21      -0.0031017000
_diffrn_orient_matrix_UB_22      0.0104218000
_diffrn_orient_matrix_UB_23      0.0599360000
_diffrn_orient_matrix_UB_31      0.0679039000
_diffrn_orient_matrix_UB_32      -0.0197331000
_diffrn_orient_matrix_UB_33      0.0129878000
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_probe          x-ray
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.0103
_diffrn_reflns_av_unetI/netI     0.0080
_diffrn_reflns_Laue_measured_fraction_full 0.997
_diffrn_reflns_Laue_measured_fraction_max 0.886
_diffrn_reflns_limit_h_max       11
_diffrn_reflns_limit_h_min       -12
_diffrn_reflns_limit_k_max       24
_diffrn_reflns_limit_k_min       -24
_diffrn_reflns_limit_l_max       16
_diffrn_reflns_limit_l_min       -15
_diffrn_reflns_number            19506
_diffrn_reflns_point_group_measured_fraction_full 0.997
_diffrn_reflns_point_group_measured_fraction_max 0.886
_diffrn_reflns_theta_full        25.242
_diffrn_reflns_theta_max         31.135
_diffrn_reflns_theta_min         3.576
_diffrn_source                   'fine-focus sealed X-ray tube'
_diffrn_source_type              'Enhance (Mo) X-ray Source'
_exptl_absorpt_coefficient_mu    0.090
_exptl_absorpt_correction_T_max  1.00000
_exptl_absorpt_correction_T_min  0.84084
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details
;
CrysAlisPro 1.171.39.20a (Rigaku Oxford Diffraction, 2015)
Empirical absorption correction using spherical harmonics,
 implemented in SCALE3 ABSPACK scaling algorithm.
;
_exptl_crystal_colour            Colourless
_exptl_crystal_density_diffrn    1.353
_exptl_crystal_description       Block
_exptl_crystal_F_000             752
_exptl_crystal_size_max          0.3
_exptl_crystal_size_mid          0.3
_exptl_crystal_size_min          0.3
_refine_diff_density_max         0.433
_refine_diff_density_min         -0.378
_refine_diff_density_rms         0.051
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.028
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     245
_refine_ls_number_reflns         5024
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.028
_refine_ls_R_factor_all          0.0409
_refine_ls_R_factor_gt           0.0389
_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^)+(0.0597P)^2^+0.7235P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1057
_refine_ls_wR_factor_ref         0.1074
_reflns_Friedel_coverage         0.000
_reflns_number_gt                4680
_reflns_number_total             5024
_reflns_threshold_expression     'I > 2\s(I)'
_cod_data_source_file            jo0c00674_si_002.cif
_cod_data_source_block           exp_361-osp-2-60etoac
_cod_database_code               4038424
_shelx_shelxl_version_number     2016/4
_reflns_odcompleteness_completeness 99.69
_reflns_odcompleteness_iscentric 1
_reflns_odcompleteness_theta     28.22
_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:
 C19(H19A,H19B)
2.b Aromatic/amide H refined with riding coordinates:
 C15(H15), C2(H2), C5(H5), C16(H16), C18(H18), C17(H17), C3(H3), C13(H13),
 C11(H11), C12(H12), C9(H9), C4(H4), C10(H10)
2.c Idealised Me refined as rotating group:
 C21(H21A,H21B,H21C)
;
_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 1.144
_oxdiff_exptl_absorpt_empirical_full_min 0.916