Sometimes chemists are able to propose two or more mechanisms that are consistent with the available data. category: benzothiophene, If a proposed mechanism predicts the wrong experimental rate law, however, the mechanism must be incorrect.Welcome to check out more blogs about 6287-82-7, in my other articles.
One of the major reasons for studying chemical kinetics is to use measurements of the macroscopic properties of a system, category: benzothiophene, such as the rate of change in the concentration of reactants or products with time.In a article, mentioned the application of 6287-82-7, Name is 2,3-Dibromobenzo[b]thiophene, molecular formula is C8H4Br2S
Cope Rearrangements in the Benzothiophene Series
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.
Sometimes chemists are able to propose two or more mechanisms that are consistent with the available data. category: benzothiophene, If a proposed mechanism predicts the wrong experimental rate law, however, the mechanism must be incorrect.Welcome to check out more blogs about 6287-82-7, in my other articles.
Reference£º
Benzothiophene – Wikipedia,
Benzothiophene | C8H6S – PubChem