Copper-Catalyzed Intramolecular Carbotrifluoromethylation of Alkynes for the Construction of Trifluoromethylated Heterocycles
作者:Yanan Wang、Min Jiang、Jin-Tao Liu
DOI:10.1002/chem.201404386
日期:2014.11.17
A mild and efficient copper‐catalyzed intramolecularcarbotrifluoromethylation of alkynes has been achieved in the presence of Togni reagent as trifluoromethylating reagent. The reaction tolerates a range of substrates to give a group of trifluoromethylatedheterocycles with high selectivities. A plausible mechanism was proposed on the basis of experimental results.
##STR1## and pharmaceutically acceptable salts thereof wherein Y is a single bond, --CH.sub.2 --, --C(O)--, --S-- or --N(R.sup.11)--; and R.sup.1 to R.sup.6 are as defined herein. These compounds have potassium channel activating activity and are useful, therefore for example, as cardiovascular agents.
Novel compounds having the formula ##STR1## wherein ##STR2## are disclosed. These compounds have potassium channel activating activity and are useful, for example, as cardiovascular agents, especially as antiischemic agents.
Benzopyran derivatives and antihypertensive use thereof
申请人:American Home Products Corporation
公开号:US04908378A1
公开(公告)日:1990-03-13
Disclosed herein are novel benzopyrans having pharmacological activity, to a process for preparing them, to pharmaceutical compositions containing them, and to their use in the treatment of hypertension.
Continuous Processing to Control a Potentially Hazardous Process: Conversion of Aryl 1,1-Dimethylpropargyl Ethers to 2,2-Dimethylchromenes (2,2-Dimethyl-2<i>H</i>-1-Benzopyrans)
作者:Ricardo J. Bogaert-Alvarez、Paul Demena、Gus Kodersha、Robert E. Polomski、N. Soundararajan、Steve S. Y. Wang
DOI:10.1021/op0100504
日期:2001.11.1
The thermal Claisen rearrangement of 4-cyanophenyl 1,1-dimethylpropargyl ether (4) to 6-cyano-2,2-dimethylchromene (5), (6-eyano-2,2-dimethyl-2H-1-benzopyran), which is used in the synthesis of a potassium channel activator drug candidate, BMS-180448, created a significant process development issue. The resulting large heat release in this conversion posed not only a safety risk but could also cause product degradation if done in a batch-wise manner. The solution was to exploit the high surface-to-volume ratio of a plug-flow reactor that would maximize the heat transfer, thereby permitting tight and responsive temperature with better reaction control. In the course of successfully testing the plug-flow concept on "micro"-flow scale (gram quantity) and "kilo"-flow scale (similar to 10 kg), a generalized mathematical model capable of predicting the reaction performance based on the physical properties of any given plug-flow reactor was generated. The model provides requisite information to design and operate a plug-flow reactor of any size for this reaction. This model would optimize reaction conditions for an acquired reactor system capable of producing similar to7 kg/h of the dimethylchromene. Application of plug-flow reactor technology enabled production of high quality 2,2-dimethylchromenes in good yield (> 98 mol %) without the use of solvents and with virtually no waste streams.