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Regio‐ and stereoselective synthesis of spiro[1‐benzothiepine‐4(5 h ), 3′(3 h )‐pyrazol]‐5‐ones
Author(s) -
Mishriky Nawal,
Girgis Adel S.,
Hosni Hanaa M.,
Farag Hanaa
Publication year - 2006
Publication title -
journal of heterocyclic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.321
H-Index - 59
eISSN - 1943-5193
pISSN - 0022-152X
DOI - 10.1002/jhet.5570430618
Subject(s) - chemistry , dehydrohalogenation , triethylamine , regioselectivity , stereoselectivity , benzene , stereochemistry , medicinal chemistry , single crystal , organic chemistry , crystallography , catalysis
Reaction of (4 E )‐4‐arylmethylene‐3,4‐dihydro‐1‐benzothiepin‐5(2 H )‐ones 3a‐e with nitrilimines (generated in situ via triethylamine dehydrohalogenation of the corresponding hydrazonoyl chlorides 4a, b ) in refluxing benzene, afforded 2′,4′,5′‐triaryl‐2,2′,3,4′‐tetrahydro‐spiro[1‐benzothiepine‐4(5 H ),3′(3 H )‐pyrazol]‐5‐ones 5a‐i and not the isomeric forms spiro[1‐benzothiepine‐4(5 H ),4′(4 H )‐pyrazol]‐5‐ones 6 in high regioselective manner. Single crystal X‐ray diffraction studies of 5a, f, g indicated that the isolated products are 3′ R , 4′ S.