Abstract:
This invention relates to a process for the preparation of 1,1-difluoroolefins, e.g., difluorovinyl cycloaliphatic compounds such as difluorovinylcyclohexane and derivatives by the dehydrofluorination of a trifluoromethyl-substituted cycloaliphatic compound and the resulting compositions. This method utilizes a "sterically hindered super-base" system represented by the formula M +- NRR - ; where M is Na or K and R is a secondary, or tertiary alkyl or cycloalkyl group of amines for effecting dehydrofluorination of the trifluoromethyl group leading to the difluorovinyl based cycloaliphatic compounds. The sterically hindered super base can be formed by the, in situ, reaction of a sodium or potassium alkoxide, e.g., K t BuO with a lithium dialkylamide where the lithium is bonded to nitrogen atom of an amine bearing secondary or tertiary aliphatic groups.
Abstract:
The invention relates to a process for the preparation of (R, R)-phenylisoserine and its derivatives. The process according to the invention includes the following steps : - reacting a 3-phenylglycidic acid salt with ammonia to yield the salt of racemic phenylisoserine, - converting the salt of racemic phenylisoserine to racemic phenylisoserine 1-4C- alkyl ester and - separating the (R,R)-phenylisoserine 1-4C-alkyl ester from the racemate by reacting the latter with L- (+)-tartaric acid and working the salt obtained for (R,R) -phenylisoserine 1-4C-alkyl ester. Likewise, D-(-)-tartaric acid can be used in order to obtain (S,S)-phenylisoserine ethyl ester in high optical purity.
Abstract:
Hypericin has been shown to specifically inhibit T-type calcium channel activity. Hypericum extract containing hypericin also inhibits T-type calcium channel activity. Moreover, other chemicals in Hypericum extract showed a synergistic effect to hypericin. In view of this, hypericin or hypericin-containing Hypericum extract can be used as T-channel blockers. Hypericum extract, extract of other species of the Hypericum genus, extract of other plants containing hypericin, hypericin derivatives, hypericin analogs, such as pseudohypericin, and other Hypericum extract constituents can be used as therapeutics targeted at T-type calcium channels for treatment of diseases associated with T-channel abnormality. Methods for administering hypericin and Hypericum extract are disclosed.
Abstract:
Disclosed is a process for the production of cyclopropylmethyl halides (CPMX) such as cyclopropylmethyl chloride (CPMCI) and cyclopropylmethyl bromide (CPMBr) wherein cyclopropanemethanol (CPMO) is contacted with an aqueous solution of a hydrogen halide (HX) at a temperature in the range of -30 °C to 35 °C. Also disclosed is a three-step process wherein CPMO is converted to a CPMX, the CPMX is separated as a liquid organic phase from the aqueous hydrogen halide by decantation and then is subjected to fractional distillation to provide CPMX in high purity. Finally, a process for the co-production of a CPMX and a cyclobutyl halide (CBX) is disclosed.
Abstract:
1-chloropropylethyne is prepared by dehydrochlorination with a base of 1-chloro-1-cyclopropylethene, which is itself prepared by treating 1-cyclopropylethanone with dichlorotriarylphosphorane or dichlorotrialkylphosphorane in the presence of a base.
Abstract:
Liquid crystal compounds which exhibit a liquid crystal phase in a wide temperature range and are lowly viscous and excellent in chemical stability and compatibility with other liquid crystal materials; liquid crystal compositions containing the compounds; and liquid crystal display devices made by using the compositions. The above liquid crystal compounds are represented by the general formula (1): Ra-A1-Z1-A2-Z2-A3-Z3-A4-Rb wherein Ra is alkenyl or alkyl wherein one or more methylene groups may be replaced by -O-, -S-, -CO-, -C C- and so on; Rb is Ra, halogeno or cyano, with the proviso that at least either of Ra and Rb must be a group containing a double bond; A1, A2, A3 and A4 are each independently trans-1,4-cyclohexylene, 1,4-phenylene, cyclohexenediyl, pyridine-2,5-diyl, pyrimidine-2,5-diyl or 1,3-dioxane-2,5-diyl; and Z1, Z2 and Z3 are each independently C2-C4 alkenylene, -(CH2)2-, -COO-, -C C-, -CH2O-, a single bond or the like, at least one of Z1, Z2 and Z3 being C2-C4 alkenylene.