The potential utility of systematic synthetic strategy will be applicable to efficient generations of chemical libraries of compounds to find ‘hit’ molecules.Read on for other articles about 6287-82-7
In heterogeneous catalysis, catalysts provide a surface to which reactants bind in a process of adsorption. The reactant in an enzyme-catalyzed reaction is called a substrate. Formula: C8H4Br2S, C8H4Br2S. A document type is Article, introducing its new discovery., Formula: C8H4Br2S
The inability to observe Cope rearrangement products at elevated temperatures for diethyl alpha-allyl-2-naphthalenemalonate (1) and diethyl alpha-allyl-9-phenanthrenemalonate (2) does not extend to the analogous systems resulting from replacement of the aromatic units by 2- and 3-benzothiophene nuclei.Thermal rearrangement of diethyl alpha-allyl-3-benzothiophenemalonate (5) at 215-255 deg C for 11 h produces the expected Cope rearrangement product diethyl 2-allyl-3-benzothiophenemalonate (10) (8percent) accompanied by trans- and cis-ethyl 2,3-dihydro-1-(ethoxycarbonyl)-1H-benzocyclopentathiophene-2-acetate (9a) (10percent) and (9b) (5percent), respectively.The structure elucidation of 10, 9a, and 9b was done by spectroscopy.The attempted structure verification of 10 by an independent route gave diethyl 2-(1-propenyl)-3-benzothiophenemalonate (12) which when heated at 230-240 deg C for 18 h gave 1-carbethoxy-2-hydroxy-3-methyldibenzothiophene (16) as a major product.Similar results were observed with 2-substituted analogues of 5, both diethyl 3-allyl-2-benzothiophenemalonate (24) and ethyl 1,2-dihydro-3-(ethoxycarbonyl)-3H-benzocyclopentathiophene-2-acetate (25) being formed.In this case the structure of 24 was verified by synthesis.An extension of this involved a study of thermal rearrangement of analogous compound ethyl alpha-allyl-alpha-cyano-3-benzothiopheneacetate (30).Thermal rearrangement of 30 at 235-245 deg C for 8 h gave the expected Cope rearrangement product ethyl alpha-cyano-2-allyl-3-benzothiopheneacetate (32) (6percent) along with an unexpected diastereomeric mixture of 1-cyano-1-(ethoxycarbonyl)-2-methyl-2,3-dihydro-1H-benzocyclopentathiophenes (33) (18percent).Speculative mechanistic considerations are offered regarding the mode of transformation of 12 to 16 and 32 to 33.
The potential utility of systematic synthetic strategy will be applicable to efficient generations of chemical libraries of compounds to find ‘hit’ molecules.Read on for other articles about 6287-82-7
Reference：
Benzothiophene – Wikipedia,
Benzothiophene | C8H6S – PubChem