Indole derivatives. 126. Substituted nitrotryptamines

A preparative method has been developed for obtaining substituted nitrotryptamines from the corresponding nitrophenylhydrazones of -phthalimidobutyraldehyde.For communication 125, see [1].Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 9, pp. 1206–1210, September, 1984.     

NMR chemical shifts. Substituted acetylenes

The MPW1PW91/6-311+G(2d,p) and MP2/6-311+G(2d,p) GIAO nuclear shieldings for a series of monosubstituted acetylenes have been calculated using the MP2/6-311G(2d,p) geometries. Axially symmetric substituents such as fluorine may lead to large changes in the isotropic shielding but have little effect on the tensor component (zz) about the C[triple bond]C bond axis. On the other hand, substituents such as vinyl and aldehyde groups lead to essentially no difference in the isotropic shielding but are calculated to give a large zz paramagnetic shift to the terminal carbon of the acetylene group, without having much effect on the inner carbon. The tensor components of the chemical shifts for trimethylsilylacetylene, methoxyacetylene, and propiolaldehyde have been measured and are in reasonable agreement with the calculations. The downfield shift at the terminal carbon of propiolaldehyde along with a small upfield shift at the adjacent carbon has been found to result from the coupling of the in-plane pi MO of the acetylene with the pi* orbital that has a node near the central carbon. The tensor components for acetonitrile also have been measured, and the shielding of cyano and acetylenic carbons are compared.     

Tetraanthraquinonoporphyrazines: I. Substituted 2,3-Dicarboxyanthraquionones

New procedures were developed for preparing substituted 2,3-dicarboxyanthraquinones by acylation of arenes with pyromellitic anhydride, followed by intramolecular cyclization of the products. The 2,3-dicarboxyanthraquinones prepared were further modified by oxidation, sulfonation, nitration, and reduction.__________Translated from Zhurnal Obshchei Khimii, Vol. 75, No. 7, 2005, pp. 1215–1220.Original Russian Text Copyright © 2005 by Borisov, Maizlish, Shaposhnikov.     

Modified Coumarins. 6. Synthesis of Substituted 5,6-Benzopsoralens

Substituted 5H-benzo[c]furo[3,2-g]chromen-5-ones, modified analogs of psoralen that contain a benzene ring annelated at the 5,6-position of a furo[3,2-g]chromen-7-one system, were synthesized from 3-hydroxy- 6H-benzo[c]chromen-6-ones.     

Modified Coumarins. II. Mannich Reaction of Substituted 4-Phenylcoumarins

Aminomethylation of 5-hydroxy- and 7-hydroxy-4-phenylcoumarins by substituted 1,1-diaminomethanes is studied. Mannich condensation of amino acids and their esters with 7-hydroxy-4-phenylcoumarin gives a series of 8-aminoacylmethylcoumarins and 4-phenyl-9,10-dihydro-2H,8H-chromeno[8,7-e][1,3]oxazin-2-ones     

Substituted pyrimidines. II. 1,3-Dimethylisocytosine and related compounds

1,3-Dimethyl-1,2-dihydro-2-imino-4(3H)pyrimidinone (1,3-dimethylisocytosine) was prepared by methylation of 2-amino-3-methyl-4(3H)pyrimidinone and was degraded in alkaline solution to a mixture of 3-methyl-2-methylamino-4(3H)pyrimidinone, 1,3-dimethyl-2,4-(1H,3H)pyrimid-indione, 2-methylamino-l-methyl-4(1H)pyrimidinone, 1-methyl-2,4-(1H,3H)pyrimidindione and 3-methyl-2,4-(1H,3H)pyrimidindione. Thiation of the title compound gave both 1,2-dihydro-1,3-dimethyl-2-thio-4(3H)pyrimidinone and 1,3-dimethyl-2,4-(1H,3H)pyrimidinedithione. The title compound is a tautomerically fixed pyrimidine and its uv spectra were compared with related compounds, notably 3-methyl-2-dimethylarnino-4(3H)pyrimidinone which is also tautomerically fixed.     

Anthraquinones tautomerism: VI. Substituted 1,4,5-trihydroxyanthraquinones

1,4,5-Trihydroxy-9,10-anthraquinone and its substituted derivatives exist in equilibrium of structures distinguished by quinoid tautomerism and rotational isomerism. Their electron absorption spectra contain π₁, π*-bands corresponding to 9,10-and 1,10-, more seldom to 1,5-and 1,4-anthraquinoid structures. Of three isomeric 1,10-anthraquinones only 4,8,9-trihydroxy-1,10-antraquinones were found. All tautomer may exist as conformers with contiguous CO and OH groups not bound by an intramolecular hydrogen bond. The considerable difference in color of structurally similar substituted compounds is due to tautomerism and conformer transformations.