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.

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.

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.

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.

A new nitrogenous substance has been isolated from the seeds ofPongamia glabra and has been named Glabrin. Its composition and properties have been studied. It seems to belong to the group of complex amino acids and is non-toxic to fish.

The waxy matter of the pericarp ofEugenia jambolana was saponified using alcoholic potash. The unsaponifiable matter contained a little sterol and some essential oil. A sparingly soluble potassium salt was produced which yielded a triterpene hydroxy acid. A study of its properties and of its derivatives indicated that it is oleanolic acid. It seems to be the major component of the waxy matter.

Detailed chemical examination of the roots ofD. ferruginea has now been carried out. Of the two varieties, the rotenone-free one is further characterised by not giving any crystalline component. The rotenonebearing variety yields besides rotenone (4·3%), only a small amount of dehydro-rotenone. The chemical chaaracteristics of rotenone-bearingD. ferruginea andD. elliptica are compared. It seems to be possible to use chemical composition to distinguish one from the other.

The roots ofDerris scandens obtained from the Central Provinces of India have now been investigated in detail. From the chloroform extractives (7·0%) three crystalline substances could be isolated and characterised. There is no rotenone. The major component is scandenin, as in the case of the American sample examined by Clark; but the yield is much higher. The other two substances appear to be new compounds and are therefore named ‘Nallanin’ and ‘Chandanin’. Lonchocarpic and robustic acids are not found in the Indian roots.

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.

A detailed examination ofD. robusta has now been made and two crystalline components isolated. The main component (D.R.I.) melts at 205–6° and agrees, in general, with the properties of robustic acid described by Harper except in melting point and analytical values. The same substance (D.R.I) was also obtained from the crude sample of robustic acid supplied by the Forest Research Institute, Dehra Dun, from where Dr. Harper also got his material. The name robustic acid has been retained for it. The molecular formula, C₂₂H₂₀O₆ agrees with the results more closely. The molecule contains two methoxyls and one hydroxyl group. The acid nature of robustic acid has now been shown to be due to a phenolic hydroxyl just as in the case of scandenin and lonchocarpic acid. These three compounds seem to form a new type not having any simple relationship with rotenone.

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.

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.

Detailed chemical examination of the roots ofDerris cuneifolia has been carried out. No rotenone could be obtained but a new crystalline compound could be isolated and is named ‘Cuneifolin’. It has the molecular formula C₂₄H₂₄O₅ and contains an alcoholic hydroxyl group and a ketonic group.

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 yieldsp-hydroxy-benzoic acid with all the three compounds. In acetic acid solution scandenin and lonchocarpic acid add on two atoms of bromine; whereas robustic acid takes up 4 bromine atoms.

7-Amino-4-methyl-3-phenyl coumarin has been prepared from 4-acetamido-o-hydroxy acetophenone. The corresponding halogen substituted coumarins, which are prepared through diazotisation and Sandmeyer reactions, have been found to be highly toxic to fish.

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.

The reaction betweeno-phenylenediamine and eighteen aromatic aldehydes under acidic conditions has been investigated, and found to yield mono-and disubstituted benziminazoles in varying proportions, and in two cases, a benzodiazacycloheptatriene derivative also. Thirteen new compounds obtained have been characterised. Stepwise mechanism for the formation of the different types of products is suggested, and the influence of substitutuents in the aldehydes on the mode of the reaction and cyclisation is discussed.

1-Benzyl-2-pheny1-5-methyl- and 1-benzyl-2-phenyl-6-methylbenziminazoles have been synthesised starting from 3-nitro-p-toluidine and 4-nitro-m-toluidine respectively. The 1:2-disubstituted benziminazole obtained by the condensation of 4-methyl-o-phenylenediamine with benzaldehyde has been shown to be identical with the 6-methyl benziminazole.

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

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-o-phenylenediamine with benzaldehyde has been found to be identical with the 5-chloro isomer.

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-o-phenylenediamine with benzaldehyde has been found to be identical with the 6-nitro benziminazole.

The condensation of 4-chloro-o-phenylenediamine with two moles of seventeen aromatic aldehydes under acidic conditions has been found to yield mono and disubstituted benziminazoles in varying proportions. The influence of substituents in the aldehydes on the mode of reaction and cyclisation has been found to be similar to that observed in the condensations witho-phenylenediamine.

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-(p-bromo phenyl) derivative is found to have the maximum activity.

On condensation with aromatic aldehydes 4-nitro-o-phenylenediamine has been found to yield mono and disubstituted benziminazoles, as well as mono or dianils in a few cases. The formation of monosubstituted benziminazoles or monoanils in greater proportion in these condensations than in those with methyl and chloro diamines may be attributed to the predominating influence of the nitro group of the diamine. The results provide strong support to the step-wise mechanism for the formation of benziminazoles through the intermediate anils.

7-Bromo and 7-bromo-4-methyl coumarins have been prepared by the Pechmann condensation ofm-bromo phenol. From the halo-substitutedo-hydroxy acetophenones, 7-halo-4-methyl-3-phenyl, 7-halo-4-hydroxy, 7-halo-4-methyl-3-cyano and 6-bromo-4-methyl-3-phenyl coumarins have been synthesised.

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.

Optimum conditions have been worked out for the condensation of urea with aromatic aldehydes and ammonium acetate. 2-Keto-4, 6-diarylhexahydro-s-triazines and 1, 3-bis-(arylidene) ureas have been prepared using eight substituted benzaldehydes in the condensations. Their ultra-violet and infrared absorption data are recorded for characterisation.

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-s-triazines have been obtained in all the cases in better yields; 1, 3-bis-arylidene thioureas could be isolated only in a few cases. The ultraviolet and infrared absorption data for some of the thioketo-hexahydro-s-triazines are recorded and the >C = S stretching frequency in these compounds has been assigned.

The condensation of resorcinol and 4-chloro resorcinol with chloro-and nitro-substitutedβ-resorcylic acids, has yielded the corresponding tetrahydroxy benzophenones, which with the exception of those containing nitro groups, could be cyclised to the respective 3:6-dihydroxy xanthones. In the case of condensations with orcinol, however, 1:6-dihydroxy xanthones could be directly isolated. A number of halo and nitro derivatives of 3:6-dihydroxy xanthone have also been prepared by direct halogenation and nitration of the xanthone, as well as by substitution in the intermediate benzophenone and subsequent cyclisation.

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.

2-Aryl benzoxazoles have been prepared in good yield by the condensation ofo-amino phenol with aromatic aldehydes in nitrobenzene medium. Starting from 4-nitro, 4-chloro and 5-nitroo-amino phenols, 5 and 6 substituted 2-aryl benzoxazoles have also been synthesised.

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.

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.

Eight representative aromatic aldehydes with hydroxy, methoxy, nitro and chloro substituents have been condensed withs-diphenyl urea and ammonium acetate resulting in 2-keto-1, 3, 4, 6-tetra-aryl-hexahydro-s-triazines. The condensation of phenyl urea with five aldehydes and ammonium acetate, however, gave 1-phenyl-1:3-bis-(α-hydroxy aryl) ureas. The ultra-violet and infra-red spectra of these two types of compounds have been recorded.

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.

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.

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.

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.

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.

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.

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.

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.

N-(o-nitro aryl)- and N-(o-acetamino aryl)-2, 5-dimethyl pyrroles are synthesized by Paal-Knorr reaction by condensing acetonyl acetone witho-nitro anilines ando-acetamino anilines respectively. Reduction of the nitro aryl pyrroles and hydrolysis of acetamino aryl pyrroles yielded the corresponding N-(o-amino aryl)-2, 5-dimethyl pyrroles.

The mode of formation of keto-hexahydro-s-triazines has been studied by conducting the reaction in two stages. The experiments revealed that the condensation with aromatic aldehydes is more complex, and the mechanism is not clear, although in the case of aliphatic aldehydes the step-wise formation of hexahydro-s-triazines has been reported.

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.

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.

7-Hydroxy-3-methyl 4-phenylcoumarin andα-methyl dihydrofurano,α andγ-pyrono ring systems have been built on 7, 8-position of 4-phenylcoumarin. The bacteriostatic activity of these compounds as well as that of mammeisin and mesuol isolated fromMesua ferrea seeds has been evaluated. Structure-activity relationship among these compounds is discussed.

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.

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.

α-Methyldihydrofurano,γ andα-pyrono ring systems have been built on 7, 8-position of 2-(2-furyl)-3-methyl chromone. The structure-activity relationship among 2-(2-furyl)-chromones is discussed.

The synthesis of combretol, annulatin, and europetin—naturally occurring partial methyl ethers of myricetin—is described. Condensation of 2, 4, 6-trihydroxy-ω-methoxyacetophenone with tri-O-methyl galloyl chloride or tri-O-benzyl galloyl chloride furnished the appropriate 3-methoxyflavones, which by a series of reactions furnished the natural myricetin derivatives.

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.

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 ofo-hydroxyacetophenones with 1, 3-diphenyl-pyrazoIe-4-carboxaldehyde under alkaline conditions. The 3-hydroxy chromones have been converted to their methyl ethers for testing their physiological properties. The structures of these compounds have been established by their analytical and spectral characteristics. All the compounds have been tested against bacteria and fungi and among them, 2-[4-(1, 3-diphenyl]-pyrazolyl)-3-methoxy chromone is found to be active at 20 ppm againstBacillus subtilis.

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.

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 ofo-aminobenzamide either with aromatic aldehydes in nitrobenzene or Schiff bases in acetic acid has yielded 2-aryl-4 (3H)-quinazolinones.

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.