A Practical and Efficient Process for the Preparation of Tazarotene
Frigoli, Samuele; Fuganti, Claudio; Malpezzi, Luciana; Serra, Stefano; Organic Process Research & Development 9 (2005) 646–; doi:10.1021/op050080x

data_1506789
_publ_section_title
;
 A Practical and Efficient Process for the Preparation of Tazarotene
;
_journal_issue                   5
_journal_name_full               'Organic Process Research &amp; Development'
_journal_page_first              646
_journal_paper_doi               10.1021/op050080x
_journal_volume                  9
_journal_year                    2005
_chemical_formula_moiety         'C21 H21 N O2 S'
_chemical_formula_sum            'C21 H21 N O2 S'
_chemical_formula_weight         351.45
_chemical_melting_point          108&#x00B0;C
_chemical_name_common            tazarotene
_chemical_name_systematic
;
 6-(2-(4,4-dimethyl-thiochroman-6yl)ethynyl)-nicotinic acid ethyl ester
;
_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                 95.980(7)
_cell_angle_gamma                90.00
_cell_formula_units_Z            4
_cell_length_a                   8.8790(10)
_cell_length_b                   9.4160(10)
_cell_length_c                   22.361(2)
_cell_measurement_reflns_used    63
_cell_measurement_temperature    293(2)
_cell_measurement_theta_max      35.0
_cell_measurement_theta_min      5.6
_cell_volume                     1859.3(3)
_computing_cell_refinement       'XSCANS (Siemens, 1996)'
_computing_data_collection       'XSCANS (Siemens, 1996)'
_computing_data_reduction        'XSCANS (Siemens, 1996)'
_computing_molecular_graphics    'SHELXTL/NT (Sheldrick, 1999)'
_computing_publication_material  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution    'SIR97 (Altomare et al., 1999)'
_diffrn_ambient_temperature      293(2)
_diffrn_measured_fraction_theta_full 0.974
_diffrn_measured_fraction_theta_max 0.974
_diffrn_measurement_device_type  'Siemens P4'
_diffrn_measurement_method       \q/2\q
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_source         'fine-focus sealed tube'
_diffrn_radiation_type           CuK\a
_diffrn_radiation_wavelength     1.54179
_diffrn_reflns_av_R_equivalents  0.0849
_diffrn_reflns_av_sigmaI/netI    0.0547
_diffrn_reflns_limit_h_max       10
_diffrn_reflns_limit_h_min       -2
_diffrn_reflns_limit_k_max       11
_diffrn_reflns_limit_k_min       -2
_diffrn_reflns_limit_l_max       26
_diffrn_reflns_limit_l_min       -26
_diffrn_reflns_number            5182
_diffrn_reflns_theta_full        65.00
_diffrn_reflns_theta_max         65.00
_diffrn_reflns_theta_min         3.98
_diffrn_standards_decay_%        '< 0.5'
_diffrn_standards_interval_count 200
_diffrn_standards_number         3
_exptl_absorpt_coefficient_mu    1.646
_exptl_absorpt_correction_type   'not applied'
_exptl_crystal_colour            orange
_exptl_crystal_density_diffrn    1.256
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       prism
_exptl_crystal_F_000             744
_exptl_crystal_size_max          '0.6 mm'
_exptl_crystal_size_mid          '0.4 mm'
_exptl_crystal_size_min          '0.2 mm'
_refine_diff_density_max         0.322
_refine_diff_density_min         -0.409
_refine_diff_density_rms         0.059
_refine_ls_extinction_coef       0.0074(11)
_refine_ls_extinction_expression Fc^*^=kFc[1+0.001xFc^2^\l^3^/sin(2\q)]^-1/4^
_refine_ls_extinction_method     SHELXL
_refine_ls_goodness_of_fit_ref   1.057
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     277
_refine_ls_number_reflns         3089
_refine_ls_number_restraints     1
_refine_ls_restrained_S_all      1.057
_refine_ls_R_factor_all          0.0644
_refine_ls_R_factor_gt           0.0592
_refine_ls_shift/su_max          0.010
_refine_ls_shift/su_mean         0.001
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w=1/[\s^2^(Fo^2^)+(0.0996P)^2^+0.4687P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1585
_refine_ls_wR_factor_ref         0.1648
_reflns_number_gt                2765
_reflns_number_total             3089
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            op050080xsi20050525_094640.cif
_cod_data_source_block           tazar
_cod_original_sg_symbol_H-M      P21/n
_cod_database_code               1506789