Synthesis and Crystal Structure of 2,3-Diethoxycarbonyl-4-phenyl-5-morpholinyl Thiophene

1INTRoDUCTIONa-Thiocarbonylthioformamidesweresynthesizedin198ol~2i,however,thereisnoreportofthesecompoundsconcerningtheirpropertiesandreactionactivitiest33.Accordingtotheirstructure,theyseemtohavereactionwithdienophi1es,likesubsti-tutedolefinicandacetylenicdienophilestoleadcorrespondingDiels-Alderproduct.xylene(15ml),diethylbutynedioicester(O.2g,1.2mmol)wasadded,themix-turewasrefluxedfor20h,thencooledtoroomtemperatureandconcentrated.Theresiduewaspurifiedbysilicagelcolumnusingacetone/petr…

Synthesis and Crystal Structure of 2, 3-Diethoxycarbonyl-4-phenyl-5-morpholinyl Thiophene

The title compound 2, 3-diethoxycarbonyl-4-phenyl-5-morpholinylthiophene (C20H23NO5S, Mr=389. 47) was obtained by the reaction of a-thiobenzoylth-ioformmorpholine with diethyl acetylene dicarboxylate - The crystal is prismatic, spacegroup P1 ( 2), with unit cell constants 2337 observed reflections . X-ray analysis reveals that interatomic dis-tances for C(1 ) -C(2) and C(3) -C (4) are 1. 393 (4), 1. 370 (4) , respectively,which show that they are C=C double bond. The atoms of C(1 ), C(2), C(3), C(4)and S form a thiophene ring. The dihedral ang1es between thiophene ring and C(5) -C(6) -C(7) -C(8) plane, phenyl ring are 31. 42 and 43. 78, respectively. The mor-pholine ring adopts chair conformation.