61196-37-0Relevant articles and documents
CONJUGATES
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Page/Page column 77, (2020/07/14)
The present invention provides a conjugate of formula (I) and itsuse in methods of treatment, and also methods for delivering an active agent into a cell. The methods may be used to deliver an active agent into a nematode, flatworm, parasite or bacterium. The conjugate of formula (I) is: (formula (I)), wherein -D- is C1-4 alkylene or C2-4 alkenylene, preferably C2-4 alkenylene, where the alkylene or alkenylene is optionally substituted with alkyl or halo; A- is an active agent for delivery; and -RA, -RB, -RT1, -RT2, -R1, -R2, -R3, -X- and -L- are as defined herein.
Recovery preparation method of racepiquamine
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Paragraph 0080; 0081; 0082; 0085; 0087; 0089; 0091; 0093, (2018/06/12)
The invention discloses a recovery preparation method of racepiquamine-1. The preparation method comprises the following steps: dissolving a waste material S-piquamine intermediate-1 as an initial rawmaterial in a solvent; and carrying out reaction at a proper temperature in the presence of a catalyst and hydrogen at a certain pressure to prepare the piquamine intermediate-1 of racemate. The formula is as shown in the description. The configured piquamine S-1 which is not needed is efficiently, conveniently and fully operated and recovered with a high yield to obtain a racemate compound 1, and then the racemate compound is used again to prepare levopraziquantel, so that wastes can be turned into wealth, and therefore, the generation cost of the levopraziquantel is saved greatly.
Br?nsted acid-mediated cyclization-dehydrosulfonylation/reduction sequences: An easy access to pyrazinoisoquinolines and pyridopyrazines
Rao, Ramana Sreenivasa,Ramanathan, Chinnasamy Ramaraj
, p. 428 - 440 (2017/03/14)
An efficient and alternative synthetic approach has been developed to prepare various N-(arylethyl)piperazine-2,6-diones from 4-benzenesulfonyliminodiacetic acid and primary amines using carbonyldiimidazole in the presence of a catalytic amount of DMAP at ambient temperature. Piperazine-2,6-diones are successfully transformed to pharmaceutically useful pyridopyrazines or pyrazinoisoquinolines and ene-diamides via an imide carbonyl group activation strategy using a Br?nsted acid. Subsequent dehydrosulfonylation reactions of the ene-diamides, in a one pot manner, smoothly transformed them to substituted pyrazinones. A concise synthesis of praziquantel (1) has also been achieved through this method.