- The first efficient synthesis and optical resolution of monosubstituted cyclotribenzylenes
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A new and high yielding synthetic route to monosubstituted cyclotribenzylenes 6 via the cyclocondensation of benzene with a suitably monosubstituted diol 20, obtained from ozonolysis of the corresponding dibenzosuberene precursor 19, was developed for the first time! The dibenzosuberene itself could be readily prepared in large quantities from inexpensive starting materials in five steps. Using this synthetic approach, a mono bromosubstituted cyclotribenzylene 12a was synthesized on large scale. Another four monosubstituted cyclotribenzylenes 21-24 were also prepared either via bromine/lithium exchange followed by subsequent quenching with external electrophiles or a copper mediated reaction with cyanide. These molecules adopt a rigid crown conformation as shown by X-ray analysis and temperature dependent NMR studies. The barrier to inversion is quite high, requiring temperatures well above 120°C before inversion takes place. Futhermore, such monosubstituted cyclotribenzylenes are planar chiral and after optical resolution, using HPLC, we were able to obtain the first planar chiral Cl-symmetric cyclotribenzylenes in form of the optically pure enantiomers of 12a, the CD spectra of which are exact mirror images over the entire spectral range.
- Schmuck, Carsten,Wienand, Wolfgang
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p. 655 - 663
(2007/10/03)
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- Synthesis of new substituted dibenzosuberones
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The multistep synthesis of new monosubstituted amides of dibenzosuberone series is described starting from 3-bromobenzosuberone; N-(3- dimethylaminopropyl)- 10,11 -dihydro-5H-dibenzo[a,d]cycloheptene-5-one- 3carboxamide 4 and N-(3-dimethylaminopropyl)-3-chloro-dibenzosuberonyl [4',12'-b]thiophene-2-carboxamide 7.
- Mikotic-Mihun, Zvonimira,Dogan, Jasna,Litvic, Mladen,Cepanec, Ivica,Karminski-Zamola, Grace M.
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p. 2191 - 2202
(2007/10/03)
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- ENDOTHELIN ANTAGONISTS INCORPORATING A CYCLOBUTANE
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Novel compounds of the general structural formula I: STR1 have endothelin antagonist activity and are therefore useful in treating cardiovascular disorders, such as hypertension, pulmonary hypertension, postischemic renal failure, vasospasm, cerebral and
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- Tricyclic compounds
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Novel tricyclic compounds having a TXA2 -antagonizing activity represented by formula (I): STR1 which strongly antagonize an action of thromboxane A2 and are expected to have preventive and therapeutic effects on ischemica diseases, cerebro-vascular diseases, etc.
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- Phenylalkylaralkylamines for pharmaceutical use
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This application discloses methods of preparing phenylalkylaralkylamines by the lithium aluminum hydride reduction of the corresponding phenylalkylaralkyl nitriles and/or amides. The produced alkylamines are converted to the corresponding N-alkyl and N,N-
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