Cyclizations of phenylethyl-substituted pyridinecarboxaldehydes
摘要:
Several phenylethyl-substituted pyridinecarboxaldehydes were prepared from 2-bromo-3-pyridinecarboxaldehyde and these substances are found to undergo cyclization reactions in acidic media. In the absence of added nucleophile, acid-promoted cyclization and oxidation (MnO2) provide an efficient route to 10,11-dihydro-5H-benzo[4,5]cyclohepta[1,2-b]pyridin-5-ones. Arene nucleophiles may also be added to the acidic mixture to provide good yields of triarylmethane products. Mechanisms are proposed involving dicationic superelectrophilic intermediates. (c) 2013 Elsevier Ltd. All rights reserved.
Cyclizations of phenylethyl-substituted pyridinecarboxaldehydes
摘要:
Several phenylethyl-substituted pyridinecarboxaldehydes were prepared from 2-bromo-3-pyridinecarboxaldehyde and these substances are found to undergo cyclization reactions in acidic media. In the absence of added nucleophile, acid-promoted cyclization and oxidation (MnO2) provide an efficient route to 10,11-dihydro-5H-benzo[4,5]cyclohepta[1,2-b]pyridin-5-ones. Arene nucleophiles may also be added to the acidic mixture to provide good yields of triarylmethane products. Mechanisms are proposed involving dicationic superelectrophilic intermediates. (c) 2013 Elsevier Ltd. All rights reserved.
Piperazine derivative or its salt, process for producing the same and
申请人:Toyama Chemical Co., Ltd.
公开号:US04948796A1
公开(公告)日:1990-08-14
A piperazine derivative represented by the following formula or a salt thereof: ##STR1## which is useful for curing cerebro-vascular disease and post-cerebro-vascular disease.