摘要:
Ethynylcyclopropane is prepared from (1,1-dimethoxyethyl)cyclopropane by a two-stage elimination of methanol. Ethynylcyclopropane is an intermediate in the synthesis of pharmaceutically active ingredients, for example, antiviral agents.
摘要:
Provided is a process for the preparation of enantiomerically pure 1-substituted-3-aminoalcohols, particularly of (S)-(−)- and (R)-(+)-3-N-methylamino-1-(2-thienyl)-1-propanol, by asymmetrically hydrogenating salts of a carboxylic acids with an aminoketone of formula (II), wherein R1 is selected from the group consisting of 2-thienyl, 2-furanyl and phenyl, each optionally substituted with one or more halogen atoms and/or one or more C1-4-alkoxy groups, and wherein R2 is C1-4-alkyl or phenyl, each optionally substituted with one or more halogen atoms and/or one or more C1-4-alkyl or C1-4-alkoxy groups, and wherein the corresponding aminoalcohols are obtained by subsequent hydrolysis of their salts. Furthermore provided are salts of a carboxylic acid with said aminoketones and the aminoalcohols obtained by asymmetriacally hydrogenating said aminoketones, respectively.
摘要:
An improved arrangement for a transverse dividing element includes an upper cross beam (32), each free end of the cross beam being guided longitudinally by way of an associated guiding structure. The guiding structure includes a slide having a groove in which a free end (34) of the cross beam (32) can slide longitudinally, the free end being equipped with guiding (92, 100) and a locking (102, 104) element. The transverse dividing element can be used to guide an upper cross beam supporting a transverse element that is used to divide the internal space of an aircraft cabin.
摘要:
The platform comprises a buoyant sub-structure comprising a base and a plurality of columns upstanding from said base, a buoyant deck-hull mounted on the columns and means for ballasting and deballasting at least the base of said sub-structure. It further comprises means for tangentially guiding said deck-hull on said columns during deployment of the platform into a predetermined configuration by ballasting of the sub-structure while the deck-hull is floating and means for locking said deck-hull to the columns in said predetermined configuration.
摘要:
A platform comprising a deck supported by a tower composed of a rigid fixed structure of the jacket type anchored to the sea floor and of an oscillating structure supported by, and connected to, the fixed structure by flexible piles anchored in the lower part of the fixed structure and arranged on the periphery of the oscillating structure, and by a shear device, the oscillating structure being equipped with a floater. The connection between the fixed and oscillating structures is located in a zone between 30 and 60% of the water depth from the water level.
摘要:
A flexible joint for connection of two pipes comprises a cup-shaped piece which can be connected to a first pipe, a tubular piece which can be connected to a second pipe, the tubular piece being coaxial with the cuplike piece and being arranged partially inside it, and two flexible spherical rings arranged between the cuplike piece and the tubular piece. The two flexible spherical rings are bolted together and arranged on opposite sides of the center of oscillation, the concave surfaces of the rings being directed towards the center of oscillation and being concentric with respect to this center.
摘要:
A process is disclosed for the preparation of a compound of formula and/or an addition salt of a proton acid, wherein R1 and R2 independently represent alkyl, cycloalkyl, aryl or aralkyl, each aryl or aralkyl being optionally further substituted with alkyl, alkoxy and/or halogen. The process involves reacting a mixture comprising a methyl ketone of formula and a compound of formula H2N—R2 (V) and/or an addition salt of proton acid, and formaldehyde in the presence of a solvent selected from the group consisting of water, aliphatic alcohols, cycloaliphatic alcohols and mixtures thereof, and optionally a proton acid to afford a β-amino ketone of formula and/or an addition salt of a proton acid, and reducing the carbonyl group of said β-amino ketone to afford a compound of formula I, and/or an addition salt of a proton acid wherein the first step is carried out at a pressure above 1.5 bar.
摘要:
A process for the preparation of N-monosubstituted β-aminoalcohol sulfonates of formula (1a), (1b): wherein R1 is C6-20-aryl or C4-12-heteroaryl, each optionally being substituted with one or more halogen atoms and/or one or more C1-4-alkyl or C1-4-alkoxy groups, R2 is C1-4-alkyl or C6-20-aryl, each aryl optionally being substituted with one or more halogen atoms and/or one or more C1-4-alkyl or C1-4-alkoxy groups, and wherein R3 is selected from the group consisting of C1-18-alkyl, C6-20-cycloalkyl, C6-20-aryl and C7-20-aralkyl residues; including a) reacting a methyl ketone, a primary amine, formaldehyde and a sulfonic acid, at a pressure above 1.5 bar, optionally in a organic solvent, said organic solvent which can include water to provide N-monosubstituted β-aminoketone sulfonates of formula (II): wherein R1, R2 and R3 are as defined above, and b) asymmetrically hydrogenating.
摘要:
The present invention relates to a process for the preparation of organic nitrates having at least one nitryloxy and at least one hydroxy group, wherein the at least one hydroxy group may be present in form of an esterified hydroxy residue, the latter being esterified with an acid other than nitric acid.
摘要:
The invention relates to an assembly of the type that comprises a guiding slide (36) consisting of a groove (40) having an inner wall which defines longitudinal guiding and/or rolling channels for complementary elements (92) borne by a guiding and/or rolling carriage (34) which is connected to a sub-assembly. The invention is characterised in that the inner wall of the groove (40) comprises at least one longitudinal electrical strip conductor (180) with which electrical contact means (190) can co-operate, said electrical contact means being borne by the guiding carriage (34) and being electrically connected to at least one associated electrical and/or electronic component of the sub-assembly. The invention can be used to guide an upper cross beam supporting a transverse element that is used to divide the internal space of an aircraft cabin.