1,2- und 1,4-Additionen methylen-aktiver Verbindungen an ein heterocyclisches Enaminon

1,2- and 1,4-Additions of Methylene-Active Compounds to a Heterocyclic Enaminone The hitherto unknown oxathiinobenzopyranones 7a-c and the dibenzoxathiines 9c-d were synthesized by 1,2- and 1,4-additions of the methylene-active compounds 3a-d to the heterocyclic enaminone 2 . Reaction pathways are proposed.     

4-(1,4-Benzochinonyl-2-)1,4-dihydropyridine als Nifedipin-Analoga

4-(1,4-Benzoquinonyl-2-)1,4-dihydropyridines as Analogues of Nifedipine 1,4-Dihydropyridines 7 and 12a , b are synthesized from 5a, b; 10a, b , and 11a , b . Oxidation yields 4-quinonyl-pyridines 6 and 14a , b . The bridged dihydropyridine 13Bb is isolated as by-product of 11 . Reduction of 14b yields 15 .     

Chinon-Amin-Reaktionen, 21. Mitt.1) Photoreaktivität einiger 2-Amino-3-halogen-1.4-naphthochinone

Quinone-Amine Reactions, XXI: Photoreactivity of 2-Amino-3-halogeno-1,4-naphthoquinones 2,3-Dichloro- and 2,3-dibromo-1,4-naphthoquinones react with the secondary amines desipramine ( A ), nor- and protriptyline ( B, C ), maprotiline ( D ) and benzoctamine ( E ) to give the 2-amino-3-chloro- and 2-amino-3-bromo-1,4-naphthoquinone derivatives 2a-e and 5a-e . Daylight dealkylates the amine function of chlorinated aminoquinones 2 exclusively, whereas in the brominated aminoquinones 5 debromination of the C-3 position neighboring the amino group is favored. Interestingly the amine functions of the debrominated products are not dealkylated.     

Photochemische Reaktivität von 5-Desazaflaviniumsalzen und 5-Desazaflavinen – ein Vergleich

Photochemical Reactivities of 5-Deazaflavinium Salts and 5-Deazaflavins The photochemical reactivities of the title compounds 3 are compared with those of 5-deazaflavins. Both groups of compounds behave similar, but the flavin analogy is rather limited with compounds of type 3a . They behave more like analogues of nicotinamide.     

Synthesis and Pharmacological Properties of 3-Amino-1,2-dihydro-3H-1,4-benzodiazepin-2-one Derivatives

Pharmaceutical Chemistry Journal -     

Chinon-Amin Reaktionen, 25. Mitt. 2-Amino-3,5,6-tribrom-1,4-benzochinone und ihre Labilität am Tageslicht

Quinone-Amine Reactions, xxv: 2-Amino-3,5,6-tribromo-1,4-benzoquinones and their instability in daylight Tetrabromo-1,4-benzoquinone (2) reacts with the amines A-F to give the blue 2-amino-3,5,6-tribromo-1,4-benzoquinones 3a-f , which were isolated by column chromatography. Additionally, the brownish yellow 2,5-diamino-3,6-dibromo-1,4-benzoquinones 4a–f are formed. All 2-amino-3,5,6-tribromo-1,4-benzoquinones (3a–f) are unstable in daylight. Debromination from the amine-neighboring C-3 gives the 2-amino-5,6-dibromo-1,4-benzoquinones 5a-e . The rate of debromination depends on the nature of the amine function. Analysis by thin-layer chromatography indicates that the reaction between 2,3-dibromo-1,4-benzoquinone (6) and the amines A–f does not yield 5a–e . 2-Amino-3,5,6-tribromo- and 2-amino-5,6-dibromo-1,4-benzoquinones were previously unknown, except for derivatives of Despiramine (1) .     

Die Kondensation von γ-und δ-Oxo-carbonsäureester mit 1,2-, 1,3- und 1,4-Alkylendiaminen

Condensation of Esters of γ- and δ-Oxocarboxylic Acids with Alkylene-1,2,1,3- and 1,4-diamines. Esters of γ-and δ-Oxocarboxylic acids condense with alkylene-1,2-, 1,3-, and 1,4-diamines and yield bicyclic lactams (5) . The path of the reaction was studied by spectroscopic methods using ethyl levulinate and N-methyl-propylene-1,2-diamine. The first step is the formation of an “aminalester” by reaction of the CO-group of ethyl levulinate with alkylene diamine, followed by intramolecular ring closure.     

4-氨基-2-氯吡啶的合成

4-氨基-2-氯吡啶(1)是医药及农药中间体[1～3],主要有以下3条合成路线:(1)2-氯-4-乙酰基吡啶与盐酸羟胺反应生成相应的肟,经Beckmann重排得到的2-氯-4-乙酰胺基吡啶再经水解制得,总收率77.8%[4,5].(2)2-氯-4-氨甲酰基吡啶在PhI(OAc)2作用下进行Hofmann重排制得,总收率85.4%[6].     

2-氨基-4′-氯-二苯甲酮的合成新法

邻苯二甲酸酐与氯苯进行付-克反应得到羧酸。然后经酰氯化。酰胺化制得2-对氯苯甲酰基苯甲酰胺，最后经霍夫曼降解合成2-氨基-4′-氯-二苯甲酮。反应条件温和。操作简便，收率78.3%。     

4-氨基-5-氯-2-乙氧基-N-[[4-(4-氟苄基)-2-吗啉基]甲基]苯甲酰胺的合成

目的合成4-氨基-5-氯-2-乙氧基-N-[[4-(4-氟苄基)-2-吗啉基]甲基]苯甲酰胺.方法以中间体4-氨基-5-氯-2-乙氧基苯甲酸和中间体B、C为原料合成目标产物.结果合成目标产物的收率为90·0%,提高近30·0%;中间体4-氨基-5-氯-2-乙氧基苯甲酸、中间体邻苯二甲酰亚胺钾、中间体B和中间体C为鲁南贝特制药有限公司生产确证.结论通过对合成路线的优化,使生产收率提高,降低成本,工艺更适于工业化的生产.     

4-(2-Amino-2-methylpropyl)phenole durch Fluoridionen-katalysierte Kondensation von 4-Hydroxybenzylalkoholen mit 2-Nitropropan

4-(2-Amino-2-methylpropyl)phenols by Fluoride Ion Catalysed Reaction of 4-Hydroxybenzyl Alcohols with 2-Nitropropane The 4-hydroxybenzyl alcohols 1 can be converted into the 4-(2-methyl-2-nitropropyl)phenols 2 by a fluoride ion catalysed reaction with 2-nitropropane. Methylation of the phenolic hydroxy group yields the methyl ethers 7. The nitro compounds 2 and 7 can be converted to the amines 8 by catalytic hydrogenation. The amines 8 are building blocks in the synthesis of new β-sympathomimetic compounds.     

N-Arylacyl- und N-Arylalkyl-Derivate von 2-Amino-1-butanol mit zwei Chiralitätszentren

N-Arylacyl and N-Arylalkyl Derivatives of 2-Amino-1-butanol with Two Chiral Centers Syntheses of all optical isomers of 2-(N-(2-phenylbutyryl)amino]-1-butanols 1a–d and 2-[N-methyl-N-(2-phenylbutyryl)amino]-1-butanols 2a–d are reported. Reduction of the amides leads to the amines 3a–d and 4a– d . Each of these compounds has two chiral centers, for which the absolute configurations are established.     

Synthesis of 4-substituted 2H-naphth[1,2-b]-1,4-oxazines, a new class of dopamine agonists

A series of tricyclic oxazines, namely, the 4-substituted 2H-naphth[1,2-b]-1,4-oxazines, have been synthesized and assayed for dopamine agonist activity. One of the members of this series, compound (+)VII-15, was found to be a remarkably potent agonist in vivo when tested in the standard 6-hydroxydopamine lesioned rat assay. The absolute configuration of the compound corresponds to that found in the active isomer of apomorphine. Its activity at the alpha 2 receptor (vs. [3H]clonidine) is relatively low. It also failed to stimulate the synthesis of cAMP in the carp retina assay, thus giving the compound a highly selective profile in favor of the D2 receptor.     

2-Amino-2′-[18F]fluorobenzhydrols,intermediates for the synthesis of [2′-18F]-1,4-benzodiazepine-2-ones

A method for synthesizing ¹⁸F-labelled 2-amino-2′-fluorobenzhydrols under nocarrier-added conditions for use as radiolabelled intermediates in the synthesis of[2′-¹⁸F]-1,4-benzodiazepine-2-ones is presented. Anilinodichloroborane reagents were formed by the reaction of boron trichloride with 4-chloro-N-methylaniline, 6a , 4-nitro-N-methylaniline, 6b , 4-nitro-N-ethylaniline, 6c , and 4-chloro-N-(2,2,2-trifluoroethyl)aniline, 6d . 2-[¹⁸F]Fluorobenzaldehyde, 5 , synthesized in 55–70% yields by the nucleophilic aromatic substitution of 2-nitrobenzaldehyde with the Kryptofix/K⁺ complex of [¹⁸F]F⁻, was subsequently reacted with the anilinodichloroborane coupling reagents with aromatic substitution occurring ortho to the amino group. The resulting 2-amino-2′-[¹⁸F]fluorobenzhydrols, 7a - 7d , were produced in conversions of 60–95% with reaction time ⩽ 10 min at room temperature or 60°C, depending on the aniline used. The total synthesis time, including evaporation of the target water, was 60–65 min. The total radiochemical conversions were of the order of 50–65% for 7a - 7c and 35–45% for 7d , decay-corrected and based on [¹⁸F]F⁻.