Transformations of 4-Amino-5-cyanopyrimidines. The Synthesis and Transformations of Pyrimido-/4,5-d/Pyrimidines

Several new approaches to the synthesis of pyrimido/4,5- -d/pyrirnidines are described. 5-Cyano-4-(N,N dimethylaminomethyleneamino)- 2-methylthiopyrimidine (2) and 5-cyano-4-ethoxyethyleneamino- 2-methylthiopyirimidine (12) cyclize with hydrazine into 3-amino-4-imino-2-methylthio-3,4-dihydropyrimido/4,5-d/pyrimidine (3) which can be deaminated into 4-amino-2-methylthiopyrimido/ 4,5-d/pyrimidine (4). On the other hand, 5-cyano-4-hydroxyiminomethyleneamino- 2-methylthio- (14) and -2-methoxopyrimidine (15) cyclize thermally into 4-amino-7-methylthio- (16) and 4-amino-7-methoxypyrimido/4,5-d/pyrimidine 3-oxide (17), respectively

Syntheses of Some Binaphthalenes

Syntheses of binaphthalene derivatives are described with the particular aim of connecting two naphthalene units in an unsymmetrical manner. 1.2\u27-Binaphthalenes were formed in a reaction between 2.3-dichloro-1.4-naphthoquinone and 1- or 2- naphthol, but the reaction can proceed further to pentacyclic quinones. Some methoxynaphthalenes were treated with vanadium oxytrichloride to give the corresponding binaphthalene derivatives, Some syntheses of unsymmetrically substituted binaphthalenes from 2-naphthol and its methoxy analog are also described

Lignin of spruce wood

Smrekov lignin je zapleten naravni klobčičasti polimer, ki še do danes ni v celoti raziskan. Temu je vzrok velika heterogenost, ki izhaja iz starosti drevesa, rastnih pogojev, mesta odvzema vzorca, letnega časa, načina izoliranja, itd. Smrekov lignin je z esterskimi, eterskimi in glikozidnimi vezmi vezan predvsem na lesne polioze, zato je popolna izolacija lignina iz lesa ovirana oziroma, praktično onemogočena. Ena izmed možnosti proučevanja lignina je tudi proučevanje biosinteze lignina, ki omogoča dodatno razumevanje strukture lignina, kar je pri drugih destruktivnih metodah oteženoSpruce lignin is complicated natural three-dimensional polymer and it\u27s structure is not known completely till today. The reason for this is it\u27s great heterogenity, which is influenced by various factors: age of tree, growing conditions, place of sample, year season, way of isolation, etc. Spruce lignin is with ester, eter and glicosides bonds tied mainly on wood polioses and for that reason the totaly isolation of lignin from wood is impediment respectively practically imossible. One way of researching lignin is researching it\u27s biosynthesis, which enables further knowing of lignin structure, what is more difficult with other destructive method