The Elusive Paal-Knorr Intermediates in the Trofimov Synthesis of Pyrroles: Experimental and Theoretical Studies.
Sączewski, Jarosław; Fedorowicz, Joanna; Gdaniec, Maria; Wiśniewska, Paulina; Sieniawska, Emilia; Drażba, Zuzanna; Rzewnicka, Justyna; Balewski, Łukasz; The Journal of organic chemistry 82 (2017) 9737–9743; doi:10.1021/acs.joc.7b01851

data_4033079
_publ_section_title
;
 The Elusive Paal-Knorr Intermediates in the Trofimov Synthesis of
 Pyrroles: Experimental and Theoretical Studies.
;
_journal_issue                   18
_journal_name_full               'The Journal of organic chemistry'
_journal_page_first              9737
_journal_page_last               9743
_journal_paper_doi               10.1021/acs.joc.7b01851
_journal_volume                  82
_journal_year                    2017
_chemical_formula_moiety         'C13 H14 N2 O4'
_chemical_formula_sum            'C13 H14 N2 O4'
_chemical_formula_weight         262.26
_chemical_name_systematic
'(Z)-Ethyl 3-(4,6-dimethyl-3-oxoisoxazolo[3,4-b]pyridin-1(3H)-yl)acrylate'
_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'
_symmetry_space_group_name_Hall  '-P 2ybc'
_symmetry_space_group_name_H-M   'P 1 21/c 1'
_atom_sites_solution_hydrogens   geom
_audit_creation_date             2017-07-21
_audit_creation_method
;
Olex2 1.2
(compiled 2017.03.28 svn.r3405 for OlexSys, GUI svn.r5337)
;
_cell_angle_alpha                90
_cell_angle_beta                 107.943(5)
_cell_angle_gamma                90
_cell_formula_units_Z            4
_cell_length_a                   12.5735(6)
_cell_length_b                   6.9794(3)
_cell_length_c                   15.5620(8)
_cell_measurement_reflns_used    1980
_cell_measurement_temperature    294.67(10)
_cell_measurement_theta_max      23.2480
_cell_measurement_theta_min      3.2200
_cell_volume                     1299.23(11)
_computing_cell_refinement       'CrysAlisPro 1.171.38.41 (Rigaku OD, 2015)'
_computing_data_collection       'CrysAlisPro 1.171.38.41 (Rigaku OD, 2015)'
_computing_data_reduction        'CrysAlisPro 1.171.38.41 (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 2014/5 (Sheldrick, 2014)'
_diffrn_ambient_environment      air
_diffrn_ambient_temperature      294.67(10)
_diffrn_detector                 'CCD plate'
_diffrn_detector_area_resol_mean 16.1544
_diffrn_detector_type            Eos
_diffrn_measured_fraction_theta_full 0.998
_diffrn_measured_fraction_theta_max 0.998
_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     -6.00  84.00   1.00    9.00    --   15.59  57.00-150.00   90
  2  \w    -25.00  25.00   1.00    9.00    --  -16.76 -99.00 -30.00   50
  3  \w    -38.00  52.00   1.00    9.00    --  -16.76  57.00   0.00   90
  4  \w    -90.00  56.00   1.00    9.00    --  -16.76   0.00 -30.00  146
  5  \w    -25.00   8.00   1.00    9.00    --   15.59 -99.00 -90.00   33
  6  \w     -6.00  68.00   1.00    9.00    --   15.59  57.00 -90.00   74
;
_diffrn_measurement_device       'four-circle diffractometer'
_diffrn_measurement_device_type  'Xcalibur, Eos'
_diffrn_measurement_method       '\w scans'
_diffrn_orient_matrix_type
'CrysAlisPro convention (1999,Acta A55,543-557)'
_diffrn_orient_matrix_UB_11      0.0410654000
_diffrn_orient_matrix_UB_12      0.0704048000
_diffrn_orient_matrix_UB_13      0.0192820000
_diffrn_orient_matrix_UB_21      0.0309152000
_diffrn_orient_matrix_UB_22      -0.0296823000
_diffrn_orient_matrix_UB_23      -0.0288811000
_diffrn_orient_matrix_UB_31      -0.0294808000
_diffrn_orient_matrix_UB_32      0.0669994000
_diffrn_orient_matrix_UB_33      -0.0330413000
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_probe          x-ray
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.0402
_diffrn_reflns_av_unetI/netI     0.0442
_diffrn_reflns_Laue_measured_fraction_full 0.998
_diffrn_reflns_Laue_measured_fraction_max 0.998
_diffrn_reflns_limit_h_max       14
_diffrn_reflns_limit_h_min       -14
_diffrn_reflns_limit_k_max       8
_diffrn_reflns_limit_k_min       -8
_diffrn_reflns_limit_l_max       18
_diffrn_reflns_limit_l_min       -13
_diffrn_reflns_number            10801
_diffrn_reflns_point_group_measured_fraction_full 0.998
_diffrn_reflns_point_group_measured_fraction_max 0.998
_diffrn_reflns_theta_full        25.021
_diffrn_reflns_theta_max         25.021
_diffrn_reflns_theta_min         3.227
_diffrn_source                   'fine-focus sealed X-ray tube'
_diffrn_source_type              'Enhance (Mo) X-ray Source'
_exptl_absorpt_coefficient_mu    0.101
_exptl_absorpt_correction_T_max  1.00000
_exptl_absorpt_correction_T_min  0.98049
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details
;
CrysAlisPro 1.171.38.41 (Rigaku Oxford Diffraction, 2015)
Empirical absorption correction using spherical harmonics,
 implemented in SCALE3 ABSPACK scaling algorithm.
;
_exptl_crystal_colour            colourless
_exptl_crystal_colour_primary    colourless
_exptl_crystal_density_diffrn    1.341
_exptl_crystal_description       prism
_exptl_crystal_F_000             552
_exptl_crystal_size_max          0.4
_exptl_crystal_size_mid          0.2
_exptl_crystal_size_min          0.1
_refine_diff_density_max         0.223
_refine_diff_density_min         -0.188
_refine_diff_density_rms         0.036
_refine_ls_extinction_coef       0.012(3)
_refine_ls_extinction_expression Fc^*^=kFc[1+0.001xFc^2^\l^3^/sin(2\q)]^-1/4^
_refine_ls_extinction_method     'SHELXL-2016/6 (Sheldrick 2016)'
_refine_ls_goodness_of_fit_ref   1.058
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     177
_refine_ls_number_reflns         2285
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.058
_refine_ls_R_factor_all          0.0903
_refine_ls_R_factor_gt           0.0527
_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^)+(0.0692P)^2^+0.1589P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1346
_refine_ls_wR_factor_ref         0.1570
_reflns_Friedel_coverage         0.000
_reflns_number_gt                1439
_reflns_number_total             2285
_reflns_threshold_expression     'I > 2\s(I)'
_cod_data_source_file            jo7b01851_si_002.cif
_cod_data_source_block           3a
_cod_database_code               4033079
_shelx_shelxl_version_number     2016/6
_chemical_oxdiff_formula         'C13 H14 N2 O4'
_shelx_estimated_absorpt_t_max   0.990
_shelx_estimated_absorpt_t_min   0.961
_reflns_odcompleteness_completeness 98.58
_reflns_odcompleteness_iscentric 1
_reflns_odcompleteness_theta     26.32
_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,H,H) groups
 At 1.5 times of:
  All C(H,H,H) groups
2. Others
 Sof(H12D)=Sof(H12E)=Sof(H12F)=1-FVAR(1)
 Sof(H12A)=Sof(H12B)=Sof(H12C)=FVAR(1)
3.a Secondary CH2 refined with riding coordinates:
 C18(H18A,H18B)
3.b Aromatic/amide H refined with riding coordinates:
 C5(H5), C13(H13), C14(H14)
3.c Disordered Me refined as rotating group:
 C12(H12A,H12B,H12C,H12D,H12E,H12F)
3.d Idealised Me refined as rotating group:
 C11(H11A,H11B,H11C), C19(H19A,H19B,H19C)
;
_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 1.037
_oxdiff_exptl_absorpt_empirical_full_min 0.932