摘要:
A gas laser, includes:a tube having two ends to be filled with gas; anda plate-shaped window hermetically sealing at least one of the ends of the tube;the window including a carrier plate and a layer coating the inside of the carrier plate;the tube being formed of a first material with a first thermal coefficient of expansion (H.sub.1) at least in vicinity of the one end thereof having the window;the layer being formed of a second material with a second thermal coefficient of expansion (H.sub.2);the carrier plate being formed of a third material with a third thermal coefficient of expansion (H.sub.3);the first and second materials being unadapted to each other; andthe third material being thermally matched to the first material.
摘要:
The manufacture of optically active bifunctional compounds of the general formula ##STR1## wherein R represents protected hydroxymethyl, protected formyl or alkoxycarbonyl and R.sup.1 represents a group of the formula ##STR2## or --CH.sub.2 --CH.dbd.NR.sup.2 in which R.sup.2 and R.sup.3 represent lower alkyl or cycloalkyl or R.sup.2 and R.sup.3 together with the nitrogen atom represent a heterocyclic ring,by isomerizing compounds of the general formula ##STR3## wherein R, R.sup.2 and R.sup.3 have the above significance and R.sup.3 can additionally signify hydrogen,is described.The compounds of formula I are potential intermediates in the manufacture of, inter alia, natural vitamin E and natural vitamin K.sub.1.
摘要:
A dental irradiation device comprises a first light emitting unit for emitting blue light adapted for light hardening of a dental material. The device further comprises a second light emitting unit and an image sensing unit which are adapted for cooperation with each other for simultaneous illumination and image capturing. The device facilitates hardening of dental materials and provides, inter alia, additional diagnostic functions.
摘要:
This invention relates to a process of the preparation of the novel intermediate (S)-4-fluoromethyl-dihydro-furan-2-one of the formula and with its use for the manufacture of pyrido[2,1-a]isoquinoline derivatives of the formula which are useful for the treatment and/or prophylaxis of diseases which are associated with DPP IV.
摘要:
The invention relates to a process for the preparation of pyrido[2,1-a] isoquinoline derivatives of the formula wherein R2, R3and 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:
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-trimethylhydroquinone-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-3enyl]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:
The present invention relates to the manufacture of the compounds of formula (I) said compounds of formula (I), or their lithium salts, are valuable intermediates in the manufacture of Dolastatin 10 analogues, which are useful in the treatment of cancer.
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-trimethylhydroquinone-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-3enyl]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:
The invention is concerned with new phosphine ligands of formula I wherein R1 and R2 are independently of each other unsubstituted alkyl, aryl, cycloalkyl or heteroaryl, or alkyl, aryl, cycloalkyl or heteroaryl each of which independently is substituted by alkyl, alkoxy, halogen, hydroxy, amino, mono- or dialkylamino, aryl, —SO2—R7, —SO3−, —CO—NR8R8′, carboxy, alkoxycarbonyl, trialkylsilyl, diarylalkylsilyl, dialkylarylsilyl or triarylsilyl; R3 is alkyl, cycloalkyl, aryl or heteroaryl; R4′ and R4 are independently of each other hydrogen, alkyl or optionally substituted aryl; or R4′ and R4 together with the C-atom they are attached, form a 3-8-membered carbocyclic ring; dotted line is optionally a double bond; R5 and R6 are independently of each other hydrogen, alkyl or aryl, R7 is alkyl or aryl; and R8 and R8′ are independently of each other hydrogen, alkyl or aryl; the substituents attached by the bold bonds are in cis relation to each other; metal complexes with such ligands in asymmetric reactions.
摘要翻译:本发明涉及式I的新的膦配体,其中R 1和R 2彼此独立地为未取代的烷基,芳基,环烷基或杂芳基,或烷基,芳基, 环烷基或杂芳基,其各自独立地被烷基,烷氧基,卤素,羟基,氨基,一或二烷基氨基,芳基,-SO 2 -R 7,-SO 3 -CO-NR 8 R 8,羧基,烷氧基羰基,三烷基甲硅烷基,二芳基烷基甲硅烷基,二烷基芳基甲硅烷基或二芳基烷基甲硅烷基 三芳基甲硅烷基 R 3是烷基,环烷基,芳基或杂芳基; R 4'和R 4彼此独立地为氢,烷基或任选取代的芳基; 或R 4'和R 4与它们所连接的C原子一起形成3-8元碳环; 虚线可选地是双键; R 5和R 6彼此独立地为氢,烷基或芳基,R 7为烷基或芳基; R 8和R 8'彼此独立地为氢,烷基或芳基; 通过粗体键连接的取代基彼此成顺式关系; 与不对称反应中的这种配体的金属络合物。
摘要:
The present invention concerns intermediates useful in and a process for the preparation of a compound of formula 1 or a salt thereof comprising a) hydroboration of a compound of formula 2 A, R1 and R2 are as herein defined. These compounds are useful in the synthesis of renin inhibitors.