N V Subba Rao
Articles written in Proceedings – Section A
Volume 10 Issue 1 July 1939 pp 1-5
Mercury compounds of succinimide and pthalimide have been obtained easily and in a pure condition by treating the respective imides with mercuric acetate in alcoholic solution. Carbamide (urea) forms two compounds when it reacts with mercuric acetate in different proportions: (I) Mercury carbamide and (2) Di-acetoxymercuri carbamide. The preparation of mercury acetamide is best effected only through the use of mercuric oxide. When mercuric acetate in alcoholic solution is employed, acetoxymercuri acetamide is formed.
Volume 10 Issue 2 August 1939 pp 65-70
A method of extracting Karanjin in good yield from Pongamia oil is described. Karanjin is only faintly bitter and is found to be useful for the treatment of leucoderma. A method of hydrolysis of Karanjin giving rise to a good yield of Karanjic acid has been found. It has been shown that Pongamia oil contains potassium in some form of chemical combination. By the action of mercuric acetate, Karanjin yields a di-acetoxy-mercuri compound.
Volume 11 Issue 1 January 1940 pp 23-27
Experiments have been conducted with a view to test if the progress of oxidation by mercuric acetate could be followed by weighing the amount of mercurous acetate precipitated from time to time. This procedure has been found to be not feasible since complications set in owing to the solvent also undergoing oxidation induced by the presence of other substances. It has been found that most compounds containing -CHOH group produce mercurous acetate in methyl alcoholic solution and the oxidation products could be identified. Convenient methods for the preparation of benzil, quinhydrone, quinone and mercurous acetate in a pure condition in the laboratory are described.
Volume 11 Issue 4 April 1940 pp 289-297
The action of mercuric chloride and mercuric acetate on the alkaloids quinine and cinchonine has been investigated with a view to prepare organomercury compounds. The properties and constitutions of the compounds have been studied. Mercuric chloride forms combinations with the basic nitrogen atoms of the alkaloids whereas with mercuric acetate it is posible to produce compounds by addition at the ethylenic double bond. Some of these can be conveniently employed for therapeutic purposes.
Volume 14 Issue 2 August 1941 pp 123-125
A new nitrogenous substance has been isolated from the seeds of
Volume 20 Issue 4 October 1944 pp 163-168
The waxy matter of the pericarp of
Volume 24 Issue 4 October 1946 pp 344-348
Detailed chemical examination of the roots of
Volume 24 Issue 4 October 1946 pp 365-374
The roots of
Nallanin has the molecular formula C26H26O5, contains one methoxyl and two hydroxyls, one of which seems to be phenolic and the other alcoholic. On the other hand, Chandanin has the molecular formula C29H30O7 possesses three methoxyls and four phenolic hydroxyls; it seems to be rather extraordinary in its characteristics.
Volume 24 Issue 5 November 1946 pp 465-472
A detailed examination of
The second component now named ‘robustenin’ melts at 188–89°, is neutral in nature and has the probable molecular formula C21H20O6. It contains two methoxyls.
Volume 25 Issue 1 January 1947 pp 22-24
The simpler methoxy flavones and some of the corresponding hydroxy compounds are markedly toxic to fish. This definitely establishes that the pyrone ring containing the atom grouping II is a toxophore.
Volume 26 Issue 1 July 1947 pp 43-45
Detailed chemical examination of the roots of
Volume 27 Issue 2 March 1948 pp 111-120
A more detailed study of scandenin is made and its important properties compared with those of lonchocarpic and robustic acids. The three non-rotenoids show marked resemblance. They do not give the Durham test, and are definitely acids owing this property not to carboxyl groups but to specially active hydroxyl groups. They are quite stable to aqueous and alcoholic alkali. The fully methylated ethers have three methoxy groups in all the three cases and these ethers undergo decomposition readily in alcoholic alkali in the presence of zinc, the main products being neutral in nature. The three compounds do not give chemical tests for the presence of carbonyl groups, exhibit definite toxicity to fish and have very similar ultra-violet absorption spectra. The toxicity and the spectra indicate the presence of carbonyl groups in conjugation with ethylenic bonds.
Oxidation with alkaline hydrogen peroxide yields
Volume 27 Issue 2 March 1948 pp 120-120 Erratum
Volume 42 Issue 5 November 1955 pp 249-251
7-Amino-4-methyl-3-phenyl coumarin has been prepared from 4-acetamido-
Volume 43 Issue 3 March 1956 pp 149-151
An improved method for the preparation of 7-amino-4-methyl coumarin is described. The corresponding halo-substituted coumarins prepared from the amino compound by diazotisation and Sandmeyer reaction have been found to be more toxic to fish than the 7-methoxy-4-methyl coumarin and far less toxic than the corresponding 3-phenyl coumarins.
Volume 43 Issue 3 March 1956 pp 173-180
The reaction between
Volume 44 Issue 5 November 1956 pp 331-337
1-Benzyl-2-pheny1-5-methyl- and 1-benzyl-2-phenyl-6-methylbenziminazoles have been synthesised starting from 3-nitro-
Volume 45 Issue 4 April 1957 pp 253-259
The reaction between 4-methyl-o-phenylene diamine and seventeen aromatic aldehydes has been investigated, and twenty-three new compounds obtained have been characterised. The results are in close agreement with those from o-phenylenediamine and aromatic aldehydes, and corroborate the inferences drawn regarding the influence of substituents in the aldehydes on the mode of the reaction and cyclisation
Volume 47 Issue 2 February 1958 pp 77-80
5-Chloro and 6-chloro, 1-benzyl-2-phenyl-benziminazoles have been synthesised starting from 4-chloro-2-nitro aniline and 5-chloro-2-nitro aniline respectively. The 1∶2-disubstituted benziminazole obtained by the condensation of 4-chloro-
Volume 47 Issue 2 February 1958 pp 81-84
1-Benzyl-2-phenyl-5-nitro benziminazole and 1-benzyl-2-phenyl-6-nitro benziminazole have been synthesised starting from N-benzyl-2∶4-dinitro aniline and 2∶5-dinitro aniline respectively. The 1∶2-disubstituted benziminazole obtained by the condensation of 4-nitro-
Volume 48 Issue 5 November 1958 pp 256-262
The condensation of 4-chloro-
Volume 49 Issue 2 February 1959 pp 96-97
7-Nitro-2-methyl-3-aryl quinazolones have been prepared by condensation of 4-nitro-N-acetyl anthranilic acid with aryl amines. These nitro quinazolones have been tested against bacteria. The 3-(
Volume 49 Issue 4 April 1959 pp 193-199
On condensation with aromatic aldehydes 4-nitro-
Volume 54 Issue 2 August 1961 pp 105-108
7-Bromo and 7-bromo-4-methyl coumarins have been prepared by the Pechmann condensation of
Volume 54 Issue 6 December 1961 pp 321-324
5-Nitro, 5-nitro-3-phenyl, 7-nitro-3-phenyl, 5-nitro-3-acetyl, 6-nitro-3-acetyl, 8-nitro-3-acetyl, 8-nitro-4-methyl-3-phenyl, 8-nitro-4-methyl-3-cyano and 8-nitro-4-hydroxy coumarins have been prepared.
Volume 55 Issue 3 March 1962 pp 185-193
Optimum conditions have been worked out for the condensation of urea with aromatic aldehydes and ammonium acetate. 2-Keto-4, 6-diarylhexahydro-
Volume 55 Issue 5 May 1962 pp 284-289
Under the optimum conditions worked out for the condensation of urea, aromatic aldehydes and ammonium acetate, the reaction has been extended to thiourea. 2-Thioketo-4, 6-diaryl hexahydro-
Volume 57 Issue 5 May 1963 pp 280-287
The condensation of resorcinol and 4-chloro resorcinol with chloro-and nitro-substituted
Volume 58 Issue 6 December 1963 pp 336-342
5- and 5:7-dihalo, 5-methoxy-7-halo and 5-methoxy-7-nitro, 5-halo-6-methoxy and 5-nitro-6-methoxy coumarones have been synthesised by condensing the appropriately substituted salicylaldehydes with bromomalonic ester.
Volume 59 Issue 6 June 1964 pp 396-402
2-Aryl benzoxazoles have been prepared in good yield by the condensation of
Volume 61 Issue 3 March 1965 pp 139-145
2-Aryl naphth-(1, 2) and naphth-(2, 1) oxazoles have been prepared by condensing 2-amino 1-naphthol and 1-amino 2-naphthol hydrochlorides respectively with nine aldehydes. The isomeric naphthoxazoles can be distinguished by the IR and UV absorption spectra.
Volume 61 Issue 3 March 1965 pp 177-185
4-Methyl 6-amino, 3-phenyl 4-methyl 6-amino and 4-methyl 8-amino umbelliferones have been condensed with a few aromatic aldehydes to obtain the corresponding (6, 7) or (7, 8) coumarino oxazoles. U.V. and I.R. spectra are recorded for some of the coumarino oxazoles.
Volume 64 Issue 3 September 1966 pp 141-147
Eight representative aromatic aldehydes with hydroxy, methoxy, nitro and chloro substituents have been condensed with
Volume 66 Issue 6 December 1967 pp 301-305
A few halo, nitro and methoxy substituted 1:2-naphthoquinones with the substituents in both the benzenoid and the quinonoid rings have been synthesised and evaluated for their fungistatic properties. Among the quinonoid compounds tested 3:4-dichloro-1:2-naphthoquinones exhibited the highest activity.
Volume 67 Issue 1 January 1968 pp 31-36
A few 5:6- and 5:8-quinoline quinones have been synthesised by oxidising the corresponding aminohydroxy and diaminoquinolines. The required aminohydroxy quinolines could be prepared by nitrosation of hydroxy quinolines and subsequent reduction. Coupling the monoamino quinolines with diazotised sulphanilic acid and reduction afforded the diamino quinolines. 6:7-Dichloro- and 6:7-dibromo-5:8-quinoline quinones exhibited fungistatic activity nearly equal to that of 2:3-dichloro-1:4-naphthoquinone.
Volume 67 Issue 1 January 1968 pp 42-49
A number of 3-amino-4-hydroxy coumarins substituted in the benzene ring have been synthesised by two methods starting from 4-hydroxy coumarins, one by nitration and reduction, and the other by diazotisation-coupling and reduction. The amino hydroxy coumarins have been converted into the corresponding (3 : 4) oxazoles by condensation with aromatic aldehydes. The ultraviolet and infrared spectral data as well as their bacteriostatic and fungistatic properties are presented.
Volume 68 Issue 6 December 1968 pp 314-323
New data presented regarding the influence of different types of substituents in the benzene ring of aromatic carbonyl compounds (including benzils) on the > C=O frequency have made it possible to revise and rationalise older explanations.
Based on uniform considerations of polarisation, rational explanation can be provided for the effects of ethylene and phenyl conjugation, hydrogen bond formation and complex formation. Abnormal effects are observed in special cases where other important factors are simultaneously involved as for example in N-oxides and flavonoids of various types; but they are explicable on a rational basis. Further, the behaviour of acetylene and nitrile compounds throws insight on the nature of some of these factors.
Volume 69 Issue 1 January 1969 pp 66-66 Erratum
Volume 69 Issue 2 February 1969 pp 88-93
The synthesis of a few (7, 8) oxazolo-flavones has been carried out starting from 7-hydroxy-8-amino flavone. The ultraviolet and infrared spectra of these new class of heterocyclic compounds have been studied. The anti-bacterial and anti-fungal activities of these compounds have been reported.
Volume 69 Issue 6 June 1969 pp 289-289 Erratum
Volume 70 Issue 2 August 1969 pp 81-88
Methylation and benzylation of 5 (or 6)-methyl benzimidazoles has been carried out under uniform conditions. The structures of the products obtained have been established by comparison with authentic samples prepared by unambiguous methods. The results obtained are explained on the basis of inductive effect of the methyl group and the relative basicity of the two nitrogen atoms.
Volume 70 Issue 6 December 1969 pp 292-299
Methylation and benzylation of 5 (or 6)-chloro benzimidazoles have been carried out under uniform conditions and the structures of the products obtained have been established by comparison with authentic samples prepared by unambiguous methods. The results are explained on the basis of inductive (−I) and resonance (+M) effects of chlorogroup and the tautomer stabilisation.
Volume 71 Issue 3 March 1970 pp 141-146
Methylation and benzylation of 5 (or 6)-nitro benzimidazoles have been carried out under, uniform conditions and the structures of the products obtained have been established by comparison with authentic samples prepared by standard methods. In each case a mixture of 1, 5- and 1, 6-isomers has been obtained, the former being comparatively in larger proportion. The results are explained on the basis of tautomer stabilisation by and the deactivating influence of nitro group.
Volume 72 Issue 1 July 1970 pp 24-29
Volume 73 Issue 2 February 1971 pp 59-63
Volume 73 Issue 5 May 1971 pp 250-256
The mode of formation of keto-hexahydro-
Volume 77 Issue 4 April 1973 pp 157-162
Volume 78 Issue 4 October 1973 pp 159-168
The synthesis of a number of 3-(2-furyl) coumarins adopting three different methods is described. The comparative merits of the methods are also discussed. The presence of a furyl moiety at the 3-posiiton of the coumarin ring has been shown to be comparatively better than a phenyl moiety in regard to the fish toxicity of the molecule. Among the coumarins tested on fish, 7-bromo-4-methyl-3-(2-furyl) coumarin has the maximum activity and is one-third as active as rotenone. The U.V., I.R. and N.M.R. spectral data of some of the compounds are also presented.
Volume 79 Issue 1 January 1974 pp 41-47
A number of 3-(3-pyridyl) coumarins with and without 4-methyl substituent have been prepared following Oglialoro and modified Perkin reactions. These compounds have been tested against fish and bacteria. Of all the compounds tested, 7-bromo-4-methyl-3-(3-pyridyl) coumarin exhibited maximum activity. A few have also shown bacteriostatic activity.
Volume 79 Issue 5 May 1974 pp 223-229
7-Hydroxy-3-methyl 4-phenylcoumarin and
Volume 79 Issue 5 May 1974 pp 230-235
1, 3-Dibenzyl-2-substituted-5-chloro benzimidazolines have been prepared from N, N2-dibenzyl-4-chloro-o-phenylenediamine and various aldehydes. Pyrolysis of these benzimidazolines yielded 1-benzyl-2-substituted-5-chloro-benzimidazoles, by preferential elimination of benzyl group from the N, meta to chloro group. Structure of the pyrolytic products has been confirmed by comparison with authentic 5-chloro and 6-chloro isomers.
Volume 80 Issue 2 August 1974 pp 93-96
Volume 80 Issue 2 August 1974 pp 97-101
The infrared and ultraviolet absorption spectra of substituted benzoins have been studied with a view to find the influence of ring substituents on the strength of chelation in benzoins. The strength of chelation was found to be in the order 4-dimethylamino benzofuroin > 4-dimethylamino benzoin > 4-methoxy benzoin = anisoin > benzoin = furoin.
Volume 80 Issue 2 August 1974 pp 102-108
Volume 80 Issue 4 October 1974 pp 168-173
The synthesis of combretol, annulatin, and europetin—naturally occurring partial methyl ethers of myricetin—is described. Condensation of 2, 4, 6-trihydroxy-
Volume 80 Issue 6 December 1974 pp 273-277
A few 4-hydroxy-3-phenylcoumarins have been synthesised from 2-hydroxy deoxybenzoins by condensing them with diethyl carbonate in the presence of sodium. By the reaction of the same deoxybenzoins with ethylorthoformate in the presence of pyridine and piperidine a few isoflavones have also been prepared. The bacteriostatic and fish-toxic properties of these compounds have been evaluated.
Volume 81 Issue 5 May 1975 pp 197-203
The synthesis of 2-[4-(1, 3-diphenyl)-pyrazolyl]-3-hydroxychromones has been carried out by AFO oxidation of 2-hydroxy-[4-(1, 3-diphenyl)-pyrazolylidine)-acetophenones. The pyrazolylidine acetophenones have been prepared by the condensation of
Volume 82 Issue 2 August 1975 pp 55-64
The influence of solvents on the intramolecular hydrogen bond in benzoin and methyl mandelate is studied using infrared spectroscopy. Non-oxygenated solvents could not break the chelation but could shift the OH frequencies to a small extent. Oxygenated solvents like diethyl ether, acetone and dioxan could break the chelation and form intermolecular hydrogen bonds. The relative intensities of the bands of intra and intermolecular hydrogen bonds gave an indication of the donor ability of these solvents, which is linked with their capacity to break the intramolecular hydrogen bonding. Making use of the symmetry numbers of the OH band, the order of the interacting abilities of the oxygenated solvents in breaking the chelation is ascertained and explained.
Volume 84 Issue 2 August 1976 pp 57-63
N-Arylidene orthanilamides undergo isomeric cyclisation in acetic acid to the corresponding 2-aryl-1, 2, 3, 4-tetrahydro-4-oxoquinazolines. The u.v. and n.m.r. spectra of some of the arylidene derivatives and their isomeric tetrahydroquinazolines have neeb studied. Condensation of
Volume 85 Issue 2 February 1977 pp 81-89
A number of 2-methyl-3-aryl-7-chloro and 2-(2-furyl)-3-aryl-4-quinazolones have been synthesised by condensing N-acyl anthranilic acids with primary aromatic amines using phosphorus trichloride in dry toluene. All these quinazolone derivatives have been screened for their antibacterial, antifungal and fishtoxic properties.