Proceedings of the Indian Academy of Sciences - Section A

Murti, V.; Seshadri, T.

doi: 10.1007/BF03172433pmid: N/A

Phloroacetophenone-2 ∶ 4-dibenzyl ether is prepared; it does not undergo persulphate oxidation satisfactorily. Monobenzylation of phloroacetophenone yields the 4-benzyl ether readily; it is partially methylated to the 2-methyl-4-benzyl ether. Starting with this compound, persulphate oxidation, Allan-Robinson condensation using benzoic anhydride and sodium benzoate and methylation produce 5 ∶ 6-dimethoxy-7-benzyloxyflavone Hydrobromic acid causes besides debenzylation, demethylation in the 5-position. The final product is the 6-methyl ether of baicalein which is identical with oroxylin-A isolated from the root and stem barks ofOroxylum indicum.

Rajagopalan, S.; Rao, P.; Rao, K.; Seshadri, T.

doi: 10.1007/BF03172434pmid: N/A

The following three partial methyl ethers of flavonols which are derivatives of naturally occurring monoglucosides having only one free hydroxyl group have been conveniently synthesised by using the method of partial benzylation: (1) 3 ∶ 5 ∶ 4′-O-trimethyl-kæmpferol derived from populnin and related glycosides, (2) 3 ∶ 5 ∶ 3′ ∶ 4′-O-tetramethyl quercetin derived from quercimeritrin and (3) 3 ∶ 5 ∶ 7 ∶ 3′ ∶ 4′-O-pentamethyl gossypetin derived from gossypin.

Rao, B.

doi: 10.1007/BF03172435pmid: N/A

Deo, P.

doi: 10.1007/BF03172436pmid: N/A

Joshi-Effect—an instantaneous and reversible diminution Δi of discharge currenti—is studied in 11 cm. chlorine excited by the silent discharge from 2 to 6 kV of 50 cycles frequency under light from a sodium vapour lamp, that from an incandescent (glass) bulb, directly; and with Wratten and other filters. RelativeJoshi-Effect %Δi=100 Δi/i p at maximum is 33% sodium light and 72% under unfiltered white. Observed with a thermopile (also with a photo-electric cell) the light intensity lay in the order, unfiltered white (50), violet (13), green (0.1) and red (21). The effect, however, varies, frequencywise. Large Δi under sodium light and red, as observed, support Joshi’s view that Δi is a quantum or frequency effect and not (entirely) a consequence of selective light-adsorption. Under a limited range of conditions, the curves %Δi—mean light frequency (ν) are almost straight lines at a series of kV, which follows simply from Joshi’s theory that a photoelectric effect from an adsorption-like boundary layer formed under the discharge is a primary change precedent to Δi.

Sastri, G.

doi: 10.1007/BF03172437pmid: N/A

In this paper, the results of field and laboratory study on the geology, petrochemistry, petrogenesis and economics of the Pachipenta Zamindari have been presented.

Nigam, Ram; Pandya, Kantilal

doi: 10.1007/BF03172438pmid: N/A

5-Chloro- and 3 ∶ 5-dichlorosalicylaldehydes have been condensed with different amides under different conditions. In contrast with the_-mono-amides obtained in all the salicylaldehyde-amide condensations,7 the monochlorosalicylaldehyde gave monoamides with only three amides, of which one, benzamide, gave the bis- product as well. The 3 ∶ 5-dichlorosalicylaldehyde gave the monoamide only once, in its condensation with benzenesulphonamide: for all the rest the-bis product was the usual rule. This may be one of the effects of the chlorine on the aromatic ring of the aldehyde. Except in one case the yields in the dichlorosalicylaldehyde-amides condensations were all higher than those of the monochloro-aldehyde-amide condensations, reaching, in condensations with propionamide and benzenesulphonamide, the quantitative limits. Usually the highest yields were obtained at 100–110° and in the absence of any condensing agent.