摘要:
A novel single-pot trialkylsilyl trifluoromethanesulfonate (R.sub.3 Si-OTf) mediated process produces derivatives of 4-aza 3-keto steroids at the .alpha.-methylenic carbon through electrophilic substitution. These derivatives are useful in the preparation, through elimination of the substituent on the .alpha.-methylene carbon, of .DELTA.-1 olefin 4-aza 3-keto steroids which are potent inhibitors of 5-.alpha. reductase.
摘要:
A novel, facile, and specific process for .alpha.-iodinating or .alpha.-brominating the .alpha.-methylenic carbon of a straight chain, branched chain, or cyclic secondary amide, such as a lactam or an azasteroid, comprises reacting the amide with trialkylsilyl-X (R.sub.3 Si--X), where X is Br, I, or Cl, and R is methyl, ethyl, or n-propyl, in the presence of I.sub.2 or Br.sub.2. The .alpha.-iodo- or .alpha.-bromo-amide is useful for making the .alpha.,.beta.-unsaturated amide through dehydrohalogenation.
摘要:
A novel single-pot trialkylsilyl trifluoromethanesulfonate (R.sub.3 Si--OTf) mediated process produces derivatives of 4-aza 3-keto steroids at the .alpha.-methylenic carbon through electrophilic substitution. These derivatives are useful in the preparation, through elimination of the substituent on the .alpha.-methylene carbon, of .DELTA.-1 olefin 4-aza 3-keto steroids which are potent inhibitors of 5-.alpha. reductase.
摘要:
A process utilizes the tetrazole functional group to direct lithiation at the ortho position of a phenyltetrazole and generate a nucleophilic aryllithium species which then undergoes reaction with an electrophile to generate a 2-substituted 1-(tetrazol-5-yl)benzene. The process is useful in the production of intermediates in the synthesis of angiotensin II antagonists. This novel process is a more cost effective and versatile route for the large-scale preparation of these key intermediates.
摘要:
A method of enhancing charged particle beam etching particularly suitable for copper interconnects, includes milling at non-contiguous locations to prevent the formation or propagation of an etch-resistant region within the rastered area. Two or more milling boxes are typically performed, one or more of the boxes having pixel spacing greater than the spot size, with the last box using a conventional pixel spacing (default mill) smaller than the spot size to produce a uniform, planar floor of the etched area.
摘要:
Imidazolmethyloxy-substituted tricyclo-macrolide immunosuppressants are prepared by reacting a tricyclo-macrolide with an imidazolmethyl trichloroacetimidate in the presence of an acid. The invention further provides a crystalline salt of imidazolmethyloxy-substituted tricyclo-macrolide, as well as novel compounds useful in the process of the present invention.
摘要:
Process for preparing 5-fluoro-2-methyl-1-(p-methylsulfinylbenzylidene)-indene-3-acetic acid by reacting fluorobenzene with an acid halide, to form an indanone, reaction of the indanone with a methylthio (or methylsulfinyl) benzyl compound to form 5-fluoro-2-methyl-1-(p-methylthiobenzyl) or (p-methylsulfinylbenzyl)-indene and reacting said indene with a glyoxylic acid.This invention relates to new processes for preparing 5-fluoro-2-methyl-1-(p-methylsulfinylbenzylidene)-indene-3-acetic acid, to intermediates thereof and processes for said intermediates.
摘要:
Process for preparing 5-fluoro-2-methyl-1-(p-methylsulfinylbenzylidene)-indene-3-acetic acid by reacting fluorobenzene with an acid halide, to form an indanone, reaction of the indanone with a methylthio (or methylsulfinyl)benzyl compound to form 5-fluoro-2-methyl-1-(p-methylthiobenzyl) or (p-methylsulfinylbenzyl)-indene and reacting said indene with a glyoxylic acid. The invention also relates to intermediates thereof and processes for said intermediates.
摘要:
A charged particle beam uniformly removes material, particularly crystalline material, from an area of a target by compensating for or altering the crystal orientation or structure of the material to be removed. The invention is particularly suited for FIB micromachining of copper-based crystalline structures. Uniformity of material removal can be improved, for example, by passing incoming ions through a sacrificial layer formed on the surface of the material to be removed. The sacrificial layer is removed along with the material being milled. Uniformity of removal can also be improved by changing the morphology of the material to be removed, for example, by disrupting its crystal structure or by altering its topography.