摘要:
Process for preparing haloketo acid derivatives [I]: ##STR1## wherein R is H or C.sub.1-6 alkyl, and X is chlorine or bromine, which comprises reacting .beta.-oxo-acid ester [II]: ##STR2## wherein R.sup.1 is H or C.sub.1-6 alkyl, R.sup.2 is C.sub.1-5 alkyl or OR.sup.3 (R.sup.3 is C.sub.1-6 alkyl), and X is the same as above, with nitrosating agent [IV]:ONOR.sup.4 [IV]wherein R.sup.4 is H, alkyl, halogen or SO.sub.3 H to give 7-halo-2-hydroxyminoheptanoic acid ester [III]: ##STR3## wherein R.sup.1 and X are the same as above, following by reacting the product with aldehyde or ketone; and intermediates therefor, and process for preparing said intermediates. Said haloketo acid derivatives are useful as intermediate for synthesis of cilastatin, which is useful as medicament, especially as dehydropeptidase inhibitor.
摘要:
Process for preparing haloketo acid derivatives [I]: ##STR1## wherein R is H or C.sub.1-6 alkyl, and X is chlorine or bromine, which comprises reacting .beta.-oxo-acid ester [II]: ##STR2## wherein R.sup.1 is C.sub.1-6 alkyl, R.sup.2 is C.sub.1-5 alkyl or OR.sup.3 (R.sup.3 is C.sub.1-6 alkyl), and X is the same as above, with nitrosating agent [IV]:ONOR.sup.4 [IV]wherein R.sup.4 is H, alkyl, halogen or SO.sub.3 H to give 7-halo-2-hydroxyiminoheptanoic acid ester [III]: ##STR3## wherein R.sup.1 and X are the same as above, followed by reacting the product with aldehyde or ketone; and intermediates therefor, and process for preparing said intermediates. Said haloketo acid derivatives are useful as intermediate for synthesis of cilastatin, which is useful as medicament, especially as dehydropeptidase inhibitor.
摘要:
An improved process for preparing an optically active 4-hydroxycyclopentenone of the formula: ##STR1## wherein R is a lower alkyl, the symbol means double bond or triple bond, and the * marked carbon is an asymmetric carbon, and the corresponding racemic 4-hydroxycyclopentenone, which are useful as an intermediate for preparing medicinal or agricultural products, particularly pharmaceutically active prostaglandins, and intermediates for preparing the optically active and/or racemic 4-hydroxycyclopentenone.
摘要:
2-Acylfuran derivatives ##STR1## (R: alkyl, phenyl, etc.; R.sub.1 : H, alkyl) are prepared in high yield by reaction, in the presence of a boron trifluoride complex catalyst, of a furan compound ##STR2## (X: H, Cl, Br; Y: Cl, Br) or with RCOOH in the presence of (XYCHCO).sub.2 O.
摘要翻译:2-呋喃基衍生物通过在三氟化硼配合物催化剂的存在下,通过在呋喃化合物(X)(X)中的反应制备高收率的(R:烷基,苯基等; R 1:H,烷基) :H,Cl,Br; Y:Cl,Br)或与RCOOH在(XYCHCO)2 O存在下反应。
摘要:
Acylaromatic compounds ##STR1## (Q: aromatic compound residue; R: straight, branched or cyclic aliphatic group, aromatic group or araliphatic group) are prepared in high yield by a reaction, in the presence of a boron trifluoride complex catalyst, of an aromatic compound with ##STR2## (X: H, Cl, Br; Y: Cl, Br) or with RCOOH in the presence of (XYCHCO).sub.2 O.
摘要:
A process for preparing an optically active cyclopentenone of the formula: ##STR1## wherein R is a hydrogen atom or a lower alkyl group and n is an integer of 4 to 8, which comprises contacting a dl-cyclopentenone ester of the formula: ##STR2## wherein R and n are each as defined above and R' is a lower alkyl group optionally substituted with halogen on an enzyme having a capability of hydrolyzing selectively either one of the d- or l-form isomer in the dl-cyclopentenone ester (II) in an aqueous medium for asymmetric hydrolysis.
摘要:
The present invention provides novel phenylacetylene compounds, liquid crystal compositions having a large refractive index anisotropy (&Dgr;n), and liquid crystal elements produced with the same. The liquid crystal composition contains at least one compound of formula (3A), and at least one compound selected from the group consisting of compounds of any one of formulae (3B) to (3C), wherein A1 to A12: alkyl group optionally substituted with F; R1, R2: H, F; A13 to A24: H, F; m: 0 or 1; Rings A to D: 1,4-phnylene, 1,4-cyclohexylene; R5, R6: H, F; Z1 to Z3: —COO—, —OCO—; b to d: 0 or 1 with b+c+d□1; B1 to B12: alkyl or alkoxy group; R7, R8: H, F:
摘要翻译:本发明提供了新的苯乙炔化合物,具有大的折射率各向异性(Deltan)的液晶组合物和由其生产的液晶元件。 液晶组合物含有至少一种式(3A)化合物和至少一种选自式(3B)至(3C)中任一项的化合物的化合物,其中A 1至A 12, :任选被F取代的烷基; R 1,R 2:H,F; A <13>至A 24:H,F; m:0或1; 环A至D:1,4-亚苯基,1,4-亚环己基; R 5,R 6:H,F; Z 1至Z 3:-COO - , - OCO-; b至d:0或1,b + c + d□1; B 1至B 12:烷基或烷氧基; R 7,R 8:H,F:
摘要:
Disclosed herein are optically active carboxylic acid or acid halide compounds of formula III: ##STR1## Wherein R.sub.2 represents an optically active alkyl or alkoxyalkyl group having 3 to 15 carbon atoms optionally substituted by halogen atoms; R' represents a hydroxyl group or a halogen atom; k is 0 or 1; and n represents an integer of 1 to 6.
摘要:
Disclosed are novel active benzene derivatives represented by the general formula (I): ##STR1## (wherein X represents --COO--, --OCO--, --CH.sub.2 O-- or --OCH.sub.2 --; A represents a hydrogen atom, a halogen atom or an alkyl or alkoxyl group having 1 to 20 carbon atoms: R represents an alkyl group having 1 to 20 carbon atoms; l and m each represents a number of 1 or 2, n represents a number of 0 or 1, but when n is 0 the sum of l and m is 3 or less; and * indicates asymmetric carbon atom), a process for producing the same, liquid-crystalline substances containing said derivatives as active ingredient, and optical switching elements utilizing the liquid crystal compositions containing said liquid-crystalline substances.
摘要:
Disclosed are novel active benzene derivatives represented by the general formula (I): ##STR1## (wherein X represents --COO--, --OCO--, --CH.sub.2 O-- or --OCH.sub.2 --; A represents a hydrogen atom, a halogen atom or an alkyl or alkoxyl group having 1 to 20 carbon atoms; R represents an alkyl group having 1 to 20 carbon atoms; l and m each represents a number of 1 or 2, n represents a number of 0 or 1, but when n is 0 the sum of l and m is 3 or less; and * indicates asymmetric carbon atom), a process for producing the same, liquid-crystalline substances containing said derivatives as active ingredient, and optical switching elements utilizing the liquid crystal compositions containing said liquid-crystalline substances.