N-methylimidazole promotes the reaction of homophthalic anhydride with imines.
Liu, Jian; Wang, Zheng; Levin, Aaron; Emge, Thomas J.; Rablen, Paul R.; Floyd, David M.; Knapp, Spencer; The Journal of organic chemistry 79 (2014) 7593–7599; doi:10.1021/jo501316m

data_4029828
_publ_section_title
;
 N-methylimidazole promotes the reaction of homophthalic anhydride with
 imines.
;
_journal_issue                   16
_journal_name_full               'The Journal of organic chemistry'
_journal_page_first              7593
_journal_page_last               7599
_journal_paper_doi               10.1021/jo501316m
_journal_volume                  79
_journal_year                    2014
_chemical_formula_moiety         'C23 H15 N O4, 0.5(C3 H8 O)'
_chemical_formula_sum            'C24.5 H19 N O4.5'
_chemical_formula_weight         399.41
_chemical_name_systematic
; 
 ? 
;
_space_group_IT_number           14
_symmetry_cell_setting           monoclinic
_symmetry_space_group_name_Hall  '-P 2yn'
_symmetry_space_group_name_H-M   'P 1 21/n 1'
_atom_sites_solution_hydrogens   geom
_atom_sites_solution_primary     direct
_atom_sites_solution_secondary   difmap
_audit_creation_method           SHELXL-97
_cell_angle_alpha                90.00
_cell_angle_beta                 98.281(1)
_cell_angle_gamma                90.00
_cell_formula_units_Z            4
_cell_length_a                   10.2269(6)
_cell_length_b                   15.8840(9)
_cell_length_c                   12.1416(7)
_cell_measurement_reflns_used    4736
_cell_measurement_temperature    100(2)
_cell_measurement_theta_max      28.91
_cell_measurement_theta_min      2.39
_cell_volume                     1951.8(2)
_computing_cell_refinement       'Bruker SAINT'
_computing_data_collection       'Bruker APEX2'
_computing_data_reduction        'Bruker SAINT'
_computing_molecular_graphics    'Bruker SHELXTL'
_computing_publication_material  'Bruker SHELXTL'
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 2008)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 2008)'
_diffrn_ambient_temperature      100(2)
_diffrn_measured_fraction_theta_full 0.999
_diffrn_measured_fraction_theta_max 0.999
_diffrn_measurement_device_type  'Bruker APEX-II CCD'
_diffrn_measurement_method       '\f and \w scans'
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_source         'fine-focus sealed tube'
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.0485
_diffrn_reflns_av_sigmaI/netI    0.0484
_diffrn_reflns_limit_h_max       13
_diffrn_reflns_limit_h_min       -13
_diffrn_reflns_limit_k_max       21
_diffrn_reflns_limit_k_min       -21
_diffrn_reflns_limit_l_max       15
_diffrn_reflns_limit_l_min       -16
_diffrn_reflns_number            18279
_diffrn_reflns_theta_full        28.28
_diffrn_reflns_theta_max         28.28
_diffrn_reflns_theta_min         2.13
_exptl_absorpt_coefficient_mu    0.094
_exptl_absorpt_correction_T_max  0.7458
_exptl_absorpt_correction_T_min  0.6865
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   'Bruker SAINT (SADABS)'
_exptl_crystal_colour            colourless
_exptl_crystal_density_diffrn    1.359
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       lathe
_exptl_crystal_F_000             836
_exptl_crystal_size_max          0.22
_exptl_crystal_size_mid          0.18
_exptl_crystal_size_min          0.14
_refine_diff_density_max         0.614
_refine_diff_density_min         -0.484
_refine_diff_density_rms         0.068
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.000
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     292
_refine_ls_number_reflns         4845
_refine_ls_number_restraints     42
_refine_ls_restrained_S_all      1.002
_refine_ls_R_factor_all          0.1040
_refine_ls_R_factor_gt           0.0725
_refine_ls_shift/su_max          0.000
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w=1/[\s^2^(Fo^2^)+(0.0700P)^2^+3.0000P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1644
_refine_ls_wR_factor_ref         0.1824
_reflns_number_gt                3458
_reflns_number_total             4845
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            jo501316m_si_003.cif
_cod_data_source_block           cmpd_15
_cod_depositor_comments
;
The following automatic conversions were performed:

'_symmetry_cell_setting' value 'Monoclinic' changed to 'monoclinic'
according to
/usr/data/users/saulius/crontab/automatic-downloads/rss-feeds/ACS/lib/dictionaries/cif_core.dic
dictionary named 'cif_core.dic' version 2.4.2 from 2011-04-26.

Automatic conversion script
Id: cif_fix_values 2281 2013-09-26 08:29:07Z andrius 

 Adding full bibliography for 4029827--4029828.cif.
;
_cod_original_cell_volume        1951.77(19)
_cod_original_sg_symbol_H-M      P2(1)/n
_cod_original_formula_sum        'C24.50 H19 N O4.50'
_cod_database_code               4029828