Synthesis of amino acid derivatives of 7-methoxycarbonylneoflavones

A number of aminoacyl derivatives of 4-phenylcoumarin have been obtained by the condensation of N-hydroxysuccinimide esters of 7-(1-carboxyalkoxy)-4-phenylcoumarins with L-amino acids and their derivatives.Kiev Taras Shevchenko University, Chemical Faculty, 252033, Kiev, Ul. Vladimirskaya, 65, tel/fax 225 12 73. Translated from Khimiya Prirodnykh Soedinenii, No. 4, pp. 464–469, July–August, 1999.     

Synthesis of carboxyalkylindolenines from 6-methyl-7-oxooctanoic acid

Novel 3-(4-carboxybutyl)indolenines were obtained. A method for the synthesis of 6-methyl-7-oxooctanoic acid, the precursor for these indolenines, was developed. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 3, pp. 595–598, March, 2008.     

Synthesis of N,O-disubtituted 3-hydroxymethyl-7-Aminocephalosporanic acid

A method has been developed for the preparation of tert-butoxycarbonylandno-3-hydroxymethylceph-2-em-4-carboxylic acid, which is an intermediate for the preparation of new antibiotic derivatives with antibacterial, anti-inflammatory, or antitumor activity.     

Synthesis and properties of derivatives of 7-aroylalkylxanthinyl-8-thioacetic acid

When 7-aroylalkyl-8-bromo-3-methyl- and 1,3-dimethylxanthines are boiled with an excess of thioglycolic acid, a reductive dehalogenation takes place, while reaction with an equimolar amount of thioglycolic acid in DMFA leads to 7-aroylalkyl-3-methyl- and 1,3-dimethylxanthinyl-8-thioacetic acids. Cyclization of the latter with acetic anhydride in the presence of anhydrous sodium acetate results in the formation of 3-aryl-1,4-dihydro-9-methyl- and-7,9-dimethylthiazino[3,2-f]xanthine.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 7, pp. 967–970, July, 1990.     

Synthesis of 7-oxo-8-aza-10a-homoprost-13-enoic acid

The synthesis of a prostaglandin E₁ analog, 7-oxo-8-aza-10a-homoprost-13-enoic acid, is reported.     

Synthesis of 3-aryl-7-nitro-3,4-dihydroisocoumarins from 4-nitrohomophthalic acid

4-Nitrohomophthalic acid reacts with aromatic aldehydes in the presence of piperidine to yield 3-aryl-7-nitro-3,4-dihydroisocoumarins. Under the same conditions, homophthalic acid yields stilbene-α,2-dicarboxylic acids.     

吡啶与GCLE碘取代物在不同溶剂中亲核取代反应动力学研究

以7-苯乙酰氨基-3-氯甲基头孢烷烯酸对甲氧基苄酯（GCLE）和吡啶为原料合成头孢他啶中间体7-苯乙酰氨基-3-吡啶甲基头孢-4-羧酸对甲氧苄酯,用高效液相色谱仪监测了吡啶与GCLE碘取代物在二氯甲烷、丙酮、四氢呋喃、乙酸乙酯和DMF混合液中的亲核取代反应,反应的动力学行为可用SN2机理来解释。在一定的溶剂中不同温度的速率常数可用Arrhenius方程很好的关联。根据Arrhenius方程求得了指前因子,进一步讨论了该反应的溶剂效应,得出在不同溶剂中亲核取代反应顺序为：乙酸乙酯-DMF混合液＞二氯甲烷＞四氢呋喃＞丙酮。     

Synthesis of 7-ethoxy- and 7-fluoro-phenothiazines

Synthesis of 7-ethoxy- and 7-fluoro-phenothiazines is reported by Smiles rearrangement of 5-ethoxy- and 5-fluoro-2-formamido-2′-nitrodiphenylsulfides. The later were obtained by the formylation of 2-amino-5-ethoxy/5-fluoro-2′-nitrodiphenylsulfides which were prepared by the condensation of 2-amino-5-ethoxy/5-fluoro-benzenethiols with o-halonitrobenzenes.     

Synthesis of 7-hydroxythioridazine and 7-hydroxysulforidazine

The thioridazine metabolites 7-hydroxythioridazine (2a) and 7-hydroxysulforidazine (2b) were synthesized. Commercial 4-chloro-3-nitrophenylmethylsulfone was converted to the corresponding 4-thiol through an intermediate xanthate ester. Subsequent zinc metal reduction provided the 3-amino thiolate. This salt was condensed with chloroquinone to yield 7-hydroxy-2-methylsulfonylphenothiazine which was then protected as the isopropyl ether. N-Alkylation with 2-(2-chloroethyl)-1-methylpiperidine using sodium hydroxide, then ether cleavage, afforded 2b . The N-alkylation followed by reduction with diisobutylaluminum hydride and deblocking yielded 2a . These reference standards will assist in an exploration of the potential role of meta-bolically formed 2a and 2b in the neuroleptic response to thioridazine.     

Synthesis of 7-Hydroxyspiropyran

The 7-acetoxyspiropyrans (4a and 4b) have been prepared by the reaction of Fischer's bases (3) with 2,4-diacetoxybenzaldehyde in refluxing ethanol in moderate yields. The acetyl group of 7-acetoxy-spiropyran 4a was easily removed to give a 7-hydroxyspiropyran 6 in high yield under the basic condition.     

Synthesis of 7-alkylpterins

Conclusions Cyclocondensation of 2,5,6-triamino-4-oxo-3,4-dihydropyrimidine with 1-phthalimido-2-alkanones in aqueous piperidine has given 7-alkylpterins.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 12, pp. 2756–2759, December, 1984.     

Synthesis of 7-alpha-methylestrone

Various ways of converting testosterone and dehydroisoandrosterone into 7α-methylestrone are described. The best method starts from dehydroisoandrosterone and gives 7α-methylestrone in a total yield of about 24% by weight.     

Synthesis of 7-azabicyclo[2.2.1]heptane-1,4-dicarboxylic acid, a rigid non-chiral analogue of 2-aminoadipic acid

A non-chiral, rigid 7-azabicyclo[2.2.1]heptane-1,4-dicarboxylic acid, an analogue of 2-aminoadipic acid, has been synthesized in six steps from dimethyl-meso-2,5-dibromohexanedioate in 28% total yield. A key step in the synthesis is double alkylation of a dimethyl pyrrolidine-2,5-dicarboxylate by 1-bromo-2-chloroethane.     

Synthesis of 2S, 3aS, 7aS- and of 2S, 3aR, 7aR-Perhydroindole-2-carboxylic acid derivatives from L-aspartic acid

Using carbon radicals generated by photolysis of N-hydroxy-2-thio-pyridone esters (mixed anhydrides) the chiral centre of L-aspartic acid has been easily incorporated into the perhydroindole structure of the title compounds.     

Synthesis of 4-chloro-7-ethoxy-2(3H)-benzoxazolone-6-carboxylic acid

As a part of metabolic studies of mosapride ( 1 ), a potential gastroprokinetic agent, the synthesis of 4-chloro-7-ethoxy-2(3H)-benzoxazolone-6-carboxylic acid ( 7 ) as a derivative of 4-amino-5-chloro-2-ethoxy-3-hydroxybenzoic acid ( 6 ), which has served a benzoic acid part of the metabolites 4 and 5 , is described. Treatment of methyl 3-amino-4-substituted amino-5-chloro-2-ethoxybenzoate derivatives 11a-c with sodium nitrate in acidic medium gave the benzotriazole derivatives 13x,y instead of the objective 3-hydroxy counterpart. The synthesis of 7 started from o-vanillin acetate ( 15 ) and proceeded through the intermediates 2-hydroxy-3-methoxy-4-nitrobenzaldehyde ( 18 ), methyl 4-amino-2,3-dihydroxybenzoate ( 23 ), and methyl 7-hydroxy-2(3H)-benzoxazolone-6-carboxylate ( 30 ). Compound 30 was alternatively prepared from 23 via methyl 4-ethoxycarbonylamino-2-ethoxycarbonyloxy-3-hydroxybenzoate ( 29 ), which is the product resulting from the migration of the ethoxycarbonyl group of methyl 4-amino-2,3-diethoxycar-bonyloxybenzoate ( 27 ).     

Synthesis of Ethyl 7-Flavonol-Oxyacetates

Ten new methoxy-, nitro-, and halogen substituted 2′-hydroxy-4-carbethoxymethoxychalcones have been prepared by the condensation of 2-hydroxy-4-carbethoxymethoxyacetophenone with substituted benzaldehydes. These chalcones have been converted to the corresponding flavonols.     

Synthesis of 1-substituted 2,3-dihydro-7H-oxepin-4-one from an amino acid

3,4-Dihydro-7H-oxepin-4-one system is potentially convenient starting material for the synthesis of diverse oxepane-based compounds such as peptidomimetics. We have developed a simple, five-step synthesis of 1-substituted-3,4-dihydro-7H-oxepin-4-one 11 from Boc-d-phenylalanine using a combination of statine synthesis methodology and olefin ring closing metathesis reaction.