Sodium Dichromate In Acetic Acid Research Articles

SYNTHESIS AND PROPERTIES OF IMIDATION PRODUCTS OF MONOSUBSTITUTED AND DISUBSTITUTED NAPHTHALIC ANHYDRIDES WITH P-AMINOBENZOIC ACID

4-Monosubstituted and 4,5-disubstituted halogeno- and nitro- N-(4-carboxyphenylnaphthalimides) were synthesized by imidation of the corresponding 4-monosubstituted and 4,5-disubstituted naphthalic anhydrides with para-aminobenzoic acid using acetic acid as solvent with 75-85% yields. 4-Amino-N- (4-carboxyphenyl)naphthalimide and 4,5-diamino-N-(4-carboxyphenyl)naphthalimide were obtained by reduction of corresponding nitrosubstituted N-(4-carboxyphenyl)naphthalimides using sodium dithionite as reducing agent in mixed ethanol-water solvent. The completion of reaction was monitored by thin layer chromatography with disappearance of the spot of the corresponding starting naphthalic anhydride. Starting 4-monosubstituted and 4,5-disubstituted naphthalic anhydrides were obtained by oxidation of corresponding substituted acenaphthenes with sodium dichromate in acetic acid. The synthesized N-carboxyphenylnaphthalimides with chlorine and bromine in positions 4 or 4 and 5 are yellow crystal substances with blue fluorescence; 4-nitro- and 4,5-dinitro-N-carboxyphenylnaphthalimides are orange crystal substances without fluorescence; 4-amino-, 4-dimethylamino and 4,5-diamino-N-carboxyphenylnaphthalimides are orange crystal substances with orange fluorescence. The structure of all the synthesized products was confirmed by IR and NMR 1H spectroscopy. The results of computer screening of the synthesized compounds using the PASS Online Internet service confirm a wide range of biological activity of N-carboxyphenylnaphthalimides, which makes them promising substances for further biological testing.

SYNTHESIS OF N-CARBOXYETHYLNAPHTHALIMIDES WITH FRAGMENTS OF PRIMARY AND SECONDARY AMINES IN POSITIONS 4 AND 5

New N-carboxyethyl-1,8-naphthalimides with fragments of morpholine and piperidine in positions 4 and 5 of naphthalene ring were synthesized by acylation of β-alanine with 4,5-dimorpholino- and 4,5-dipiperidino-1,8-naphthalic anhydrides in acetic acid. Corresponding 4,5-disubstituted naphthalic anhydrides were obtained by nucleophilic substitution of chlorine atoms in 4,5-dichloro-1,8-naphthalic anhydride on corresponding electron donating amino substitutients using dimethyl sulfoxide as solvent. Starting 4,5-dichloro-1,8-naphthalic anhydride was obtained by oxidation of 4,5-disubstituted acenaphthene with sodium dichromate in acetic acid. The same sequence of reactions can not be used for synthesis of N-carboxyethyl-1,8-naphthalimides with 2-hydroxyethylamino groups in positions 4 and 5 as the main product of reaction of 4,5-dichloro-1,8-naphthalic anhydride with ethanolamine is the product of nucleophilic addition of primary amine to carbonyl group of anhydride cycle but not the product of chlorine atoms substitution. Thus N-carboxyethyl-4,5-di(2-hydroxyethylamino)-1,8-naphthalimide was obtained by acylation of β-alanine with 4,5-dichloro-1,8-naphthalic anhydride followed by chlorine atoms substitution in N-carboxyethyl-4,5-dichloro-1,8- naphthalimide. The synthesized N-carboxyethylnaphthalimides with morpholino-, piperidino and 2-hydroxyethylamino groups in positions 4 and 5 are orange crystal substances with yellow fluorescence. Their structure was confirmed by IR and NMR 1H spectroscopy. The obtained fluorophores have weak fluorescence in aqueous solutions but their fluorescence increases 14-22 times by addition of albumin, so they can be considered as perspective substances for their further research as fluorescent probes for proteins.

Some Transformative Reactions of Odollactone

Oxidative rearrangement of odollactone has been carried out with hydrogen peroxide containing p-toluene sulphonic acid in dichloromethane. The products obtained were characterised by chemical transformation using selenium dioxide in acetic acid, sodium dichromate in acetic acid and Li in ethylenediamine followed by spectral analysis. The in- troduction of olefinic double bond at AB-ring juncture influences the cleavage of γ-lactone ring to the diol in contrast to the parent odollactone that gives the carboxylic acid.

A New Technique to Prepare 9-Oxofluorene-2-Carboxylic Acid

9-Oxofluorene-2-carboxylic acid has been obtained with a yield as high as 98.5%, following a new procedure with easy product extraction, based on the reaction of 2-acetylfluorene with sodium dichromate in acetic acid.

Triterpenoide. X. Über neue isomere Triterpenlactone

The X-ray crystal structure analyses of three new triterpene lactones (C29H42O6), namely 9β-hydroxy-28-methoxy-11,28-dioxo-1,2-dinor-10α-18β-olean-12-en-3,10β- olide, (3), its 18α- and 9α,18α-isomers, (4) and (5) [9β-hydroxy-28-methoxy-11,28-dioxo-1,2-dinor-10α-18α-olean-12-en-3,10β- olide and 9α-hydroxy-28-methoxy-11,28-dioxo-1,2-dinor-10α-18α-olean-12-en-3,10β- olide, respectively], are described. Compounds (3)–(5) are obtained by treatment of 3β-hydroxy-11-oxo-18α-olean-12-en-28-oic acid methyl ester, (1), with sodium dichromate in acetic acid. In compounds (3)–(5) the six-membered ring A of (1) is replaced by a γ-lactone ring. In contrast to compound (1), the C25 methyl group at C10 has α configuration. The newly introduced hydroxyl group at C9 is β-oriented in compounds (3) and (4), and α oriented in (5). Ring B in (3) has a boat form, but in (4) and (5) it has different equivalent chair conformations. Ring C in (3) has a sofa form, in (4), it has a slightly distorted half-chair form and in (5), it has a conformation intermediate between the half-chair and sofa forms. Rings D and E have chair conformations in all three compounds and are trans-fused in compounds (4), (5) and (1) and cis-fused in (3). In contrast to compound (1), rings A/B in compounds (3)–(5) and rings B/C in compounds (3) and (4) are cis-fused. In compounds (3)–(5), formation of hydrogen bonds has been observed. Inversion of the α configuration to a β configuration at C18 in oleanolic acid derivatives [transformation of (1) to (3)] has been observed for the first time. The triterpene lactones (3)–(5) are the first known oleanan derivatives with cis-fused A/B [(3)–(5)] and B/C rings [(3) and (4)].

Preliminary analysis of Monterey kerogen by mild stepwise oxidation with sodium dichromate in glacial acetic acid

Kerogen from Monterey shale was degraded by a controlled, mild stepwise oxidation with sodium dichromate in acetic acid. The products of each step were examined by capillary gas chromatography and combined gas chromatography-mass spectrometry analyses of their methyl esters. Major oxidation products were saturated normal monocarboxylic acids (C 6-C 34), saturated normal α,ω-dicarboxylic acids (C 4-C 34), and isoprenoid acids (C 14-C 21, except C 18). Less dominant were aromatic acids, branched monocarboxylic acids (C 6-C 16), cyclic structures, heterocyclic compounds, as well as some unidentified compounds. On the basis of the evidence obtained from the qualitative and quantitative variation of the products with duration of oxidation, the following results were obtained: 1. (a) the kerogen nucleus is mainly composed of long-chain polymethylene, cross-linked aliphatic structure from which protrude n- alkyl chains and minor amounts of isoprenoid and non-isoprenoid branched hydrocarbons; 2. (b) the periphery, compared to the nucleus, contains a greater proportion of n- alkyl and isoprenoid moieties, particularly the C 14, C 16, and C 18 n- alkyl chains as well as the C 15 and C 16 isoprenoid chains; 3. (c) other subordinate structures present include phenyl and tolyl groups as well as alicyclic and heterocyclic compounds.

Syntheses of Pyrrolotropone Derivatives from Benzocycloheptene-5,6-dione Monoarylhydrazones. II. Syntheses of Benzo[5,6]cyclohept[l,2-b]-indole-6,11,12-triones

Abstract Benzo[5,6]cyclohept[1,2-b]indole-6,11,12-triones (benzoindolotropoquinones)(VIIIa–c) were prepared by the oxidation of 11,12-dihydrobenzo[5,6] cyclohept[1,2-b]indol-6-ones (Va–c) with sodium dichromate in acetic acid. Compound VIIIa was rearranged by means of a coned sodium hydroxide solution into a known benzocarbazole-1,4-quinone. The pyrrolotropolone derivative (VII) was also obtained through the ring closure of the 5-hydrazinotropolone derivative (VI).

Studies in the synthesis of cortisone. Part IV. The oxidation of steroid 7 : 9-dienes with sodium dichromate in acetic acid

The first page of this article is displayed as the abstract.

Synthesis of Colchicine Derivatives

WHILE the methoxylated carbon-system of (IV) is conclusively established for certain degradation products of colchicine1,2, the synthesis of such unsymmetrically substituted dibenzcycloheptatrienes, necessary for further work, has hitherto miscarried, because of difficulties which are partly concealed and partly apparent2–4. A synthesis which promises to afford the requisite degree of adaptability has now been found and is based on the oxidation of appropriate 9- or 10-methylphenanthrenes with osmium tetroxide in benzene-pyridine5,6. In a model experiment, 9-methylphenanthrene (I) was thereby oxidized to 9 : 10-dihydroxy-9: 10-dihydro-9-methylphenanthrene (II), m.p. 130-131° (found: C, 79.9 ; H, 6.1 ; C15H14O2 requires C, 79.7 ; H, 6.2 per cent), from which, by cleavage with lead tetra-acetate and renewed cyclization, there was obtained the known 3 : 4 : 5 : 6-dibenzcyclohepta-1: 3 : 5-trien-7-one (III)2. Similarly, 2 : 3 : 4: 7-tetramethoxy-10-methylphenanthrene, m.p. 134–135° (found: C, 73.2 ; H, 6.4 ; C19H20O4 requires C, 73.1 ; H, 6.4 per cent), Was converted via the corresponding 9: 10-dihydro-9 : 10-diol, m.p. 156° (found: C, 66.0 ; H, 6.4 ; C19H22O6 requires C, 65.9 ; H, 6.4 per cent) into the unsaturated ketone (IV), which was identical with the part-product previously obtained1 by oxidizing deaminocolchinol methyl ether with sodium dichromate in acetic acid.