摘要:
A process for the manufacture of 3-phytyl-2,5,6-trimethylhydroquinone-1-acetate, and optionally therefrom tocopheryl acetate, comprises either C-alkylating 2,3,6-trimethylhydroquinone-1-acetate with isophytol or phytol in the presence of a sulphur(VI) containing catalyst of the formula R1SO2OH, wherein R1 signifies hydroxy, halogen, lower alkyl, halogenated lower alkyl or aryl, in an aprotic organic solvent, or O-alkylating 2,3,6-trimethylhydroquinone-1-acetate with a phytyl halide in a polar aprotic organic solvent in the presence of a base, and subjecting the so-obtained 4-O-phytyl-2,3,6-trimethylhydro-quinone-1-acetate to a rearrangement reaction, and in each case optionally submitting the so-obtained 3-phytyl-2,5,6-trimethylhydroquinone-1-acetate to a ring closure reaction to produce tocopheryl acetate. The invention also includes the novel compound 3-phytyl-2,5,6-trimethylhydroquinone-1-acetate and certain stereoisomers thereof, and also the further novel compound 4-hydroxy-2,3,6-trimethyl-5-[3-(4,8,12-trimethyltridecyl)-but-3-enyl]phenyl acetate which itself is one of several isomers of 3-phytyl-2,5,6-trimethylhydroquinone-1-acetate formed by isomerization under the influence of heating, e.g. during its distillation as part of the isolation and purification procedure following its manufacture as indicated above. (All-rac)-α-tocopherol, which may be derived from its acetate, is known to be the most active industrially important member of the vitamin E group.
摘要:
A dispensing device including a container for a supply of items forming a web. The dispensing device includes a recess formed in an outer wall of the container, a braking unit overlapping the recess. The braking unit includes two lips which work together when items are dispensed and a linear slit between the two lips which enables the items to pass between the two lips, the two lips being fitted with bristles which constitute active elements of the two lips, unattached ends of the bristles of one of the lips extend into, and mesh with, an area of unattached ends of the bristles of the opposite lip. The items are camisole-shaped and sequentially joined bags having a body with a bottom part and handles at the upper part. The bottom part of the body of one of the bags is connected to the leading edge of the handles of the next bag. A nozzle for dispensing the bags is connected to the recess, the nozzle including a hollow cover in the base of which there is an oblong and virtually linear opening, the distance between the edges of the opening being considerably larger than the thickness of a bag. The braking unit is attached to the hollow cover in such a way that it overlaps the linear opening in the hollow cover.
摘要:
The invention relates to a process for the preparation of pyrido[2,1-a] isoquinoline derivatives of the formula wherein R2, R3 and R4 are as defined in the specification, comprising the steps of a) catalytic asymmetric hydrogenation of an enamine of the formula wherein R1 is lower alkyl, in the presence of a transition metal catalyst containing a chiral diphosphane ligand, b) introduction of an amino protecting group Prot and c) amidation of the ester to form an amide of formula wherein R2, R3, R4 and Prot are as defined in the specification.
摘要:
Novel chiral amidophosphine-phosphinite compounds, which are present in (R) and (S) form, of the general formula wherein R1 signifies alkyl, cycloalkyl or aralkyl, R2 signifies alkyl, cycloalkyl, aralkyl or aryl and R3 and R4 each independently signify alkyl, cycloalkyl, aralkyl, aryl or heteroaryl or R3 and R4 together with the respective phosphorus atom signify a 9-dibenzophospholyl, 9-phosphabicyclo[3.3.1]nonyl or 9-phosphabicyclo[4.2.1]nonyl group and * denotes a chiral center, are manufactured by reacting a compound of the general formula R1C(OH)—CONHR2 (III) with a disubstituted chlorophosphane of the general formula R3R4PCl (IV) in a solvent and in the presence of a base. As ligands the amidophosphine-phosphinite compounds in accordance with the invention form complexes with Group VIII transition metals, especially with rhodium, iridium, ruthenium and palladium, and optionally with further ligands, and such complexes are likewise an object of the present invention; they can be used as catalysts for enantioselective reactions, especially for asymmetric hydrogenations, enantioselective hydrogen displacements and allylic substitution reactions.
摘要:
A process for the racemization of atropisomeric bis(phosphine oxide) compounds of formula I: in their (S) or (R) or non-racemic form, is useful for preparing optical active bisphosphine ligands, that form optical active complexes with transition metals. Racemization is thermal and carried out in high or low boiling solvent, under normal or elevated pressure at 105 to 3.5×107 Pa. Heating is performed in a system that allows heating up to 400° C. (reactor, autoclave, aluminum block, round-bottom flask with heating/stirring mantle and the like) or by microwave irradiation or in the melt at a temperature from 260 to 400° C.
摘要:
A hinge for glasses pivotably connects an endpiece (2) attached directly on a lens (3) or provided on a frame with a temple (1). The hinge has a hinge pin (12) held rotatably in a hinge support (22) of the endpiece (2), which hinge pin is disposed on the temple (1). The hinge pin (12) forms a predetermined breaking point (122) for the hinge, which releases the temple (1) when an admissible force on the endpiece (2) is exceeded. A preferred embodiment is described, according to which the hinge pin (12) is formed in one piece with the temple (1) in an injection molding process.
摘要:
The present invention is concerned with a process for the manufacture of optically active compounds of the formula ##STR1## wherein R signifies lower alkyl, lower alkoxy, phenyl, benzyl or --NR.sub.2.sup.1, R.sup.1 signifies lower alkyl, phenyl, benzyl or hydrogen and * signifies an optically active center, by asymmetrically hydrogenating an enol derivative of ketoisophorone of the formula ##STR2## wherein R has the significance given above, in the presence of a rhodium complex of an optically active diphosphine ligand.
摘要:
The invention is concerned with novel water-soluble racemic or optically active compounds of formulae ##STR1## wherein R.sup.1, R.sup.2, R.sup.3 and R.sup.4 independently signify lower alkyl or lower alkoxy;m and n are 0, 1 or 2; andX signifies hydrogen, an alkali :metal, the equivalent of an earthalkali metal or an ammonium ion;with the provision that R.sup.3 is in position 4 or 5 and R.sup.4 is in position 4' or 5'. The invention is also concerned with complexes of such compounds with a metal of Group VIII. These complexes are, useful as catalysts for asymmetric hydrogenation and for enantioselective hydrogen displacement in prochiral allylic systems.
摘要:
Novel chiral phosphorus compounds of the formula ##STR1## wherein R signifies lower alkyl, R.sup.1 signifies phenyl and R.sup.2 and R.sup.3 signify hydrogen or lower alkoxy,which are suitable in the form of complexes with a metal of Group VIII as catalysts for asymmetric hydrogenations and for enantioselective hydrogen displacements in prochiral allylic systems.