A versatile synthesis of cyclic dipeptides using the stepwise construction of the piperazine-2,5-dione ring from simple precursors: synthetic sequence and the structure of a representative product, (3<i>RS</i>)-4-(2-allyl-3,5-dimethylphenyl)-1-benzyl-3-phenylpiperazine-2,5-dione
Acosta Quintero, Lina M.; Palma, Alirio; Cobo, Justo; Glidewell, Christopher; Acta Crystallographica Section C 74 (2018) –; doi:10.1107/S2053229618000037

data_2020943
_publ_section_title
;
 A versatile synthesis of cyclic dipeptides using the stepwise
 construction of the piperazine-2,5-dione ring from simple precursors:
 synthetic sequence and the structure of a representative product,
 (3<i>RS</i>)-4-(2-allyl-3,5-dimethylphenyl)-1-benzyl-3-phenylpiperazine-2,5-dione
;
_journal_coeditor_code           YF3132
_journal_issue                   2
_journal_name_full               'Acta Crystallographica Section C'
_journal_page_first
;
;
_journal_paper_doi               10.1107/S2053229618000037
_journal_volume                  74
_journal_year                    2018
_chemical_formula_iupac          'C28 H28 N2 O2'
_chemical_formula_moiety         'C28 H28 N2 O2'
_chemical_formula_sum            'C28 H28 N2 O2'
_chemical_formula_weight         424.52
_chemical_name_systematic
(3<i>RS</i>)-4-(2-Allyl-3,5-dimethylphenyl)-1-benzyl-3-phenylpiperazine-2,5-dione
_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_method           SHELXL-2014
_cell_angle_alpha                90
_cell_angle_beta                 115.8850(10)
_cell_angle_gamma                90
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_cell_length_a                   23.3641(8)
_cell_length_b                   10.0825(3)
_cell_length_c                   21.4524(7)
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_cell_measurement_temperature    100(2)
_cell_measurement_theta_max      27.611
_cell_measurement_theta_min      2.154
_cell_volume                     4546.5(3)
_computing_cell_refinement
;
SAINT (Bruker, 2016)
;
_computing_data_collection
;
APEX3 (Bruker, 2016)
;
_computing_data_reduction
;
SAINT (Bruker, 2016)
;
_computing_molecular_graphics
;
PLATON (Spek, 2009)
;
_computing_publication_material
;
SHELXL2014 (Sheldrick, 2015) and PLATON (Spek, 2009)
;
_computing_structure_refinement
;
SHELXL2014 (Sheldrick, 2015)
;
_computing_structure_solution
;
SIR92 (Altomare <i>et al.</i>,  1994)
;
_diffrn_ambient_temperature      100(2)
_diffrn_measured_fraction_theta_full 0.997
_diffrn_measured_fraction_theta_max 0.988
_diffrn_measurement_device_type  'Bruker D8 Venture'
_diffrn_measurement_method       '\f and \w scans'
_diffrn_radiation_monochromator  'multilayer mirror'
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.0502
_diffrn_reflns_limit_h_max       30
_diffrn_reflns_limit_h_min       -30
_diffrn_reflns_limit_k_max       11
_diffrn_reflns_limit_k_min       -13
_diffrn_reflns_limit_l_max       24
_diffrn_reflns_limit_l_min       -27
_diffrn_reflns_number            35190
_diffrn_reflns_theta_full        25.242
_diffrn_reflns_theta_max         27.611
_diffrn_reflns_theta_min         2.154
_diffrn_standards_decay_%        0
_diffrn_standards_interval_count 0
_diffrn_standards_interval_time  0
_diffrn_standards_number         0
_exptl_absorpt_coefficient_mu    0.078
_exptl_absorpt_correction_T_max  0.991
_exptl_absorpt_correction_T_min  0.967
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details
;
(SADABS; Bruker, 2016)
;
_exptl_crystal_colour            colourless
_exptl_crystal_density_diffrn    1.240
_exptl_crystal_description       block
_exptl_crystal_F_000             1808
_exptl_crystal_size_max          0.150
_exptl_crystal_size_mid          0.150
_exptl_crystal_size_min          0.120
_refine_diff_density_max         0.297
_refine_diff_density_min         -0.294
_refine_ls_extinction_method     none
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_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     588
_refine_ls_number_reflns         10435
_refine_ls_number_restraints     3
_refine_ls_restrained_S_all      1.036
_refine_ls_R_factor_all          0.0787
_refine_ls_R_factor_gt           0.0490
_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^)+(0.0485P)^2^+1.7906P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1034
_refine_ls_wR_factor_ref         0.1173
_reflns_number_gt                7625
_reflns_number_total             10435
_reflns_threshold_expression     'I > 2\s(I)'
_cod_data_source_file            yf3132sup1.cif
_cod_data_source_block           I
_cod_database_code               2020943
_cod_database_fobs_code          2020943
_shelx_estimated_absorpt_t_min   0.988
_shelx_estimated_absorpt_t_max   0.991
_shelx_hkl_checksum              39128
_shelx_res_checksum              86935
_shelxl_version_number           2.014