首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 31 毫秒
1.
W. Schäfer  A. Aguado 《Tetrahedron》1973,29(18):2881-2887
2,5-Bisanilino-3-acetyl(carbomethoxy)-benzoquinones react with substituted 2-hydroxy-ethylamines to give 2-(2-hydroxyethylamino)-3-acetyl(carbomethoxy)-benzoquinones. These are converted to 2,3-dihydro-1,4-benzoxazine-6,7-quinones 5.  相似文献   

2.
3.
4.
5.
6.
7.
Synthesis of Dimethyl 4a,8a-Methanophthalazine-1,4-dicarboxylate and Derivatives Diels-Alder reaction with inversed electron demand of 1H-cyclopropabenzol 1 with dimethyl 1,2,4,5-tetrazine-3,6-dicarboxylate ( 2 ) yields dimethyl-4a,8a-methanophthalazine-1,4-dicarboxylate ( 3 ). The reactions of 3 with nucleophiles are also described.  相似文献   

8.
9.
10.
Starting from1 the azomethine2 is obtained. The intermediates4 a and4 b of this reaction sequence cause the high yields. Cyclization of theN-alkylderivatives4 d and8 b leads also to an azomethine, which is obtained as its salt11. Cyclization of theN-acetylderivative13 yields however the anamine14. The structures of the new products are established by chemical and spectroscopic methods.
Teile aus der DissertationW. Kropp, Universität Wien, 1977.  相似文献   

11.
12.
Reaction of diphenacylaniline (1) withPPA yields in dependence of reaction time the indole3 and the pyrroloindole4. The structures were established on the basis of spectroscopic methods. Action of LiAlH4 on4 forms5 by hydrogenation of one double bond and cleavage of one pyrrole ring.

Herrn Prof. Dr.F. Vieböck zum 75. Geburtstag gewidmet.  相似文献   

13.
14.
Syntheses of Dibenzo[b,e][1,4]dioxin-2,3-quinones Including the Ecklonoquinones A and B and the Isoecklonoquinones A and B Oxidation of monomesyloxy-substituted pyrocatechols with MnO2 in toluene using phase-transfer conditions leads in high yield to monomesyloxy-substituted dibenzo[b,e][1,4]dioxin-2,3-quinones with loss of one mesyloxy group. In this way, ecklonoquinone A ( 2 ), ecklonoquinone B ( 3 ), isoecklonoquinone A ( 43 ), and isoecklonoquinone B ( 44 ) were prepared. Their structures are based on X-ray analyses of ecklonoquinone-A leucoacetate ( 45 ) and the mesyloxy-substituted quinone 20 . The reddish-violet dibenzodioxin-diquinone 49 was prepared from an intermediate of the iso-series. The parent compound 1 has been synthesized in yields better than 50% from pyrocatechol and methyl 2,5-dioxo-2,5-dihydrobenzoate as oxidant and 2-methoxypyridin as catalyst. To rationalize the specific effect on the dimerisation step of the mesyloxy group, the intermediacy of 1,4-quinone monoacetals is proposed. This also applies to a proposed biogenetic scheme.  相似文献   

15.
Zusammenfassung Propionaldehyd, n-Butyraldehyd und n-Valeraldehyd reagieren mit Äthylenimin und Schwefel in Gegenwart von Dimethylformamid oder wasserfr. K2CO3 zu Gemischen von 2-monoalkylierten 5,6-Dihydro-4H-1,4-thiazinen (2–4) und 2-monoalkylierten Thiazolidinen (6–8). Bei Einsatz von Acetaldehyd in diese Reaktion konnte nur 2-Methylthiazolidin (5) isoliert werden. Durch Kondensation von -Chloraldehyden mit Cysteaminnatrium erhält man die 2-Alkyl-5,6-dihydro-4H-1,4-thiazine (2,3) als alleinige Reaktionsprodukte.Die Umsetzung von2 und3 mit Ameisensäure führt zu Gemischen von N-Formylthiomorpholinen (9, 11) und N-Formyl-5,6-dihydro-1,4-thiazinen (10, 12), aus denen man entweder durch Hydrolyse mit verd. HCl (9,1113,14) oder besser durch Hydrierung und Hydrolyse mit Natriumboranat (9,11,10 und1213,14) die entsprechenden 2-monoalkylierten Thiomorpholine gewinnt. Unsubstituiertes Thiomorpholin (15) sowie13 und14 lassen sich in besseren Ausbeuten (42–70%) gewinnen, wenn man die durch Umsetzung der -Chloraldehyde mit Cysteaminnatrium erhaltenen 5,6-Dihydro-1,4-thiazine nicht isoliert, sondern direkt mit Natriumboranat behandelt.
Synthesis of thiomorpholine and 2-monoalkylated thiomorpholines via 5.6-Dihydro-1.4-thiazines (Joint action of elementary sulfur and gaseous ammonia upon ketones, LXXII)
Propionaldehyde, n-butyraldehyde and n-valeraldehyde react with ethylenimine in the presence of dimethylformamide or anhydrous K2CO3 to mixtures of 2-monoalkylated 5.6-dihydro-4H-1.4-thiazines (2–4) and 2-monoalkylated thiazolidines (6–8). When acetaldehyde is inserted in this reaction, solely 2-methyl-thiazolidine (5) could be isolated. By condensation of -chloroaldehydes with the sodium salt of cysteamine 2-alkyl-5.6-dihydro-4H-1.4-thiazines (2,3) are obtained as the only reaction products.Reaction of2 and3 with formic acid affords mixtures of N-formylthiomorpholines (9, 11) and N-formyl-5.6-dihydro-1.4-thiazines (10, 12), which yield either by hydrolysis with dilute HCl (9, 1113, 14) or better by hydrogenation and hydrolysis with NaBH4 (9, 11, 10, and1213, 14) the corresponding thiomorpholines. Unsubstituted thiomorpholine (15) as well as13 and14 are obtained in better yields (42–70%), if the 5.6-dihydro-1.4-thiazines, synthesized by reaction of -chloroaldehydes with the cysteamine-sodium salt, are not isolated, but directly hydrogenated with NaBH4.


Herrn Prof. Dr. phil. habil.R. Tschesche zum 65. Geburtstag gewidmet.

71. Mitt.:F. Asinger, H. Offermanns, K. H. Lim undD. Neuray, Mh. Chem. (im Druck).

Teil der DissertationP. Müller, Techn. Hochschule Aachen, 1968.  相似文献   

16.
The syntheses of 3-phenyl-5-oxo-4, 5-dihydro-1,4-benzoxazepine ( 2 ) and -3-phenyl-5-ethoxy-1,4-benzoxazepine ( 14 ) are described. 2 rearranges under the influence of sodamide into the isoquinoline derivatives 4 , 5 and 6 respectively; 14 is converted quantitatively into 1-ethoxy-3-phenyl-4-hydroxy-isoquinoline ( 16 ) in boiling methanol, even in the absence of a strong base. Possible reaction mechanisms are discussed.  相似文献   

17.
18.
19.
Zusammenfassung Beim Behandeln von1-Chloracetylaminofluoren-9-on-oxim (6) mit verd. KOH entsteht 3,4-Dihydro-2H-fluoreno[1,9-ef]-1,4-diazepin-3-on-1-oxid (7); durch Erhitzen von 1-Aminoacetyl-amino-fluoren-9-on (10) sowie durch Kondensation von 1-Aminofluoren-9-on mit Glycinesterhydrochlorid wird 3,4-Dihydro-2H-fluoreno[1,9-ef]-1,4-diazepin-3-on (11) erhalten. Es wird bewiesen, daß es sich bei7 und11 um Derivate des Fluoreno[1,9-ef]-1,4-diazepins (2) handelt und daß7 das 1-Oxid von11 ist. Die Synthesen weiterer Derivate von2 werden beschrieben.
On treating the oxime of 1-chloroacetylaminofluoren-9-one (6) with dilute aqueous potassium hydroxide, 3,4-dihydro-2H-fluoreno[1,9-ef]-1,4-diazepin-3-one-1-oxide (7), is formed; heating of 1-aminoacetylaminofluoren-9-one (10) and condensation of 1-aminofluoren-9-one with glycine ester hydrochloride both yield 3,4-dihydro-2H-fluoreno[1,9-ef]-1,4-diazepin-3-one (11). It is shown that both7 and11 are derivatives of fluoreno[1,9-ef]-1,4-diazepine (2) and that7 is the 1-oxide of11. The syntheses of several other derivatives of2 are reported.


Herrn Prof. Dr.F. Wessely zum 70. Geburtstag.  相似文献   

20.
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号