Aminomethylation of cytisine by 3-hetaryl-7-hydroxychromones

8-Aminomethyl derivatives of 7-hydroxychromones were prepared by reaction of methylene-bis-cytisine with substituted 7-hydroxychromones. The structures of the synthesized compounds were investigated using NMR spectroscopy. __________ Translated from Khimiya Prirodnykh Soedinenii, No. 3, pp. 237–241, May–June, 2007.     

Aminomethylation of 3-aryl-7-hydroxycoumarins

The reaction of the analogs of natural 3-arylbenzopyran-2-ones with electrophilic reagents of aminal structure was studied. Substituted 8-aminomethyl-3-aryl-7-hydroxycoumarins were synthesized. The optimum conditions were determined for the production of 9-alkyl- and 9-(het)arylmethyl derivatives of 3-aryl-9,10-dihydro-2H,8H-chromeno[8,7-e][1,3]oxazin-2-one in the series of analogs of natural 3-arylbenzopyran-2-ones.     

1,2,4-Thiadiazole derivatives of cytisine

Several new derivatives were prepared by reaction of 3-alkylthio-5-chloroacetamido-1,2,4-thiadiazoles with cytisine.Translated from Khimiya Prirodnykh Soedinenii, No. 6, pp. 479–480, November–December, 2004.This revised version was published online in April 2005 with a corrected cover date.     

Thiazole and benzothiazole derivatives of cytisine

Several new derivatives were prepared by reacting N-1(5-R-thiazol-2-yl)-2-chloroacetamides and N-1(6-R-benzothiazol-2-yl)chloroacetamides with cytisine. __________ Translated from Khimiya Prirodnykh Soedinenii, No. 4, pp. 379–380, July–August, 2006.     

Synthesis of cytisine derivatives of coumarins

New substituted 4-chloromethylcoumarins that were used as alkylating agents to modify cytisine were synthesized by Pechmann condensation. A series of 4-(12-cytisylmethyl)coumarins containing pharmacophores of the natural heterocycles coumarin and cytisine in a single molecule was prepared. The alkylation gave the best results if diisopropylethylamine was used as the base. __________ Translated from Khimiya Prirodnykh Soedinenii, No. 5, pp. 485–488, September–October, 2007.     

Novel synthesis of 2-amino-3-hetaryl-4(5H)-oxothiophenes

3-Cyano-3-hetaryl-2-oxopropyl thioacetates were obtained by the acylation of hetarylacetonitriles with acetylmercaptoacetyl chloride. Their reaction with amines led to the formation of 2-amino-3-hetaryl-4(H)-oxothiophenes. __________ Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 5, pp. 680–685, May, 2006.     

Chemical modification of plant alkaloids. I. Aminomethylation of barbituric acid derivatives by cytisine

Reaction of cytisine with 1-mono- and 1,3-disubstituted 5-arylmethylbarbituric acids in the presence of formaldehyde results in aminomethylation of C-5 to form the corresponding 5-cytisylmethylbarbituric acids. The structures of the products are found using PMR spectroscopy and mass spectrometry. 1-Phenyl-5-(2,4-dimethoxybenzyl)-5-cytisylmethylbarbituric acid is obtained as a mixture of two steroisomers in an approximately 21 ratio.I. I. Mechnikov St. Petersburg State Medical Academy, 195067, St. Petersburg, Piskarevskii pr., 47; 2) ZAO Interbioscreen, 142432, Chernogolovka, Moscow District, Institutskii pr. 8. Translated from Khimiya Prirodnykh Soedinenii, No. 2, pp. 152–156, March–April, 2000.     

Reaction of cytisine with formalin

The reaction of cytisine with formalin in various solvents was studied. Methylene-bis-cytisine was produced in addition to the expected N-methylolcytisine in all solvents except acetone, in which N-(3-oxobutyl)cytisine was produced. __________ Translated from Khimiya Prirodnykh Soedinenii, No. 6, pp. 579–580, November–December, 2006.     

2-[6-Alkyl-3-hetaryl-4-oxo-9,10-dihydro-4H,8H-chromeno-[8,7-<Emphasis Type="Italic">e</Emphasis>][1,3]oxazin-9-yl]acetic acids

The interaction has been studied of a series of substituted 3-hetaryl-7-hydroxychromones with amino acids and formaldehyde (reactants ratio 1: 1: 2 respectively). In the case of glycine and Het = 3-isoxazolyl the product of aminomethylation at position 8 of the chromone was obtained, and with other Het (including Het = 4-phenyl-1,2,4-triazol-3-yl) 2-[6-alkyl-3-hetaryl-4-oxo-9,10-dihydro-4H,8H-chromeno[8,7-e][1,3]-oxazin-9-yl]acetic acids were formed. With β-alanine and Het = 4-phenyl-1,2,4-triazol-3-yl the corresponding β-substituted propionic acid was synthesized, but proline did not participate in the reaction, leading to bis(6-ethyl-3-hetaryl-7-hydroxychromon-8-yl)methane. __________ Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 5, pp. 683–689, May, 2007.     

Modified coumarins. 22. Synthesis of N-coumarinyloxyacetyl derivatives of cytisine

N-Acetyl derivatives of cytisine modified by coumarins were synthesized. __________ Translated from Khimiya Prirodnykh Soedinenii, No. 2, pp. 110–113, March–April, 2006.     

Synthesis and biological activity of N-benzyl derivatives of cytisine

The reductive alkylation of cytisine by various aromatic aldehydes was studied. Preliminary pharmacological investigations of the synthesized compounds were performed. __________ Translated from Khimiya Prirodnykh Soedinenii, No. 4, pp. 373–378, July–August, 2006.     

Modified coumarins. 20. Furocoumarin derivatives of cytisine

Cytisine derivatives modified by furocoumarins were synthesized using activated esters. __________ Translated from Khimiya Prirodnykh Soedinenii, No. 3, pp. 230–232, May–June, 2006.     

Synthesis of Formononetin Analogs

Derivatives of the natural isoflavone formononetin were synthesized. Acylation and alkylation of the phenolic hydroxyls and the chromone ring were investigated.     

Synthesis of analogs of natural 2′-methoxyisoflavones

2-(Un)substituted-2′-methoxy-7-hydroxyisoflavones were synthesized. They were derivatized at the phenol hydroxyl using alkylation and acylation reactions and Mannich base formation. __________ Translated from Khimiya Prirodnykh Soedinenii, No. 2, pp. 117–121, March–April, 2006.     

Synthesis of 5-amino-4-hetaryl-2,3-dihydro-1h-3-pyrrolones

2-Hetaryl-3-oxo-4-phthalimidobutyronitriles (and pentanonitriles) were obtained with high yields by C-acylation of hetarylacetonitriles with N-phthaloylglycine and -alanine chlorides respectively under the conditions of base catalysis. Hydrazinolysis of the phthaloyl protection in these compounds leads to the formation of 5-amino-4-hetaryl-2,3-dihydro-1H-3-pyrrolones.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 12, pp. 1783–1790, December, 2004.     

Aminomethylation of hindered 2-propargyl-1,3-diketones

2-Propargyl-substituted methoxy-1,3-diketones react with alkoxymethylamines or paraform and secondary amines in the presence of CuCl at the acetylene group to afford Mannich bases.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 5, pp. 1293–1295, May, 1996.     

Synthesis of N-aminoglycosides of the alkaloid cytisine

A series of new N-aminoglycosides of the alkaloid cytisine based on industrially available monosaccharides D-glucose, D-galactose, D-xylose, and L-arabinose was synthesized and characterized. The optimal methods for condensing and isolating the products were found. The structures and position of cytisine in the glycosides were proved by PMR spectroscopy. Translated from Khimiya Prirodnykh Soedinenii, No. 6, pp. 596–597, November–December, 2008.