R C Shah
Articles written in Proceedings – Section A
Volume 7 Issue 4 April 1938 pp 266-268
Rhizonaldehyde, 3 : 6-dimethyl-4-methoxy-2-hydroxy benzaldehyde, has been synthesised directly from orcinol. Orcinol was converted into orcylaldehyde, and this on nuclear methylation by methyl-alcoholic KOH and MeI, afforded rhizonaldehyde.
Volume 23 Issue 4 April 1946 pp 179-181
Methyl-2∶3∶4-trihydroxy benzoate was formylated by the action of hexamethylene-tetramine in glacial acetic acid and methyl-2∶3∶4-trihydroxy-5-formyl benzoate was obtained. Several derivatives of the formyl ester were prepared and the structure established.
Formylation of several hydroxy compounds was also attempted.
Volume 23 Issue 4 April 1946 pp 182-186
Methyl-2-hydroxy-1-formyl-3-naphthoate was synthesised by the action of hexamethylene-tetramine on methyl-2-hydroxy-3-naphthoate.
Similar formylation of methyl-2-hydroxy-1-naphthoate was attempted with negative results.
Volume 23 Issue 4 April 1946 pp 187-191
The action of hexamethylene tetramine on phenols and the methyl esters of phenol carboxylic acids - Part IV. The synthesis and study of methyl-1-hydroxy-4-formyl 2-naphthoate and 2-acetyl-4-formyl-α-naphthol
Methyl-1-hydroxy-4-formyl-2-naphthoate and 2-acetyl-4-formyl-α-naphthol have been synthesised by the action of hexamethylene tetramine in glacial acetic acid, on methyl-1-hydroxy-2-naphthoate and 2-acetyl-α-naphthol respectively.
Similar formylation of 4-acetyl-α-naphthol did not succeed.
Volume 23 Issue 5 May 1946 pp 305-306
The action of acetic anhydride on methyl-γ-resorcylate in presence of anhydrous aluminium chloride afforded methyl-2∶6-dihydroxy-3-acetyl-benzoate and 2∶6-dihydroxy-3-acetyl-benzoic acid.
Volume 23 Issue 6 June 1946 pp 338-340
Some important and interesting derivatives of 2:4-dihydroxy-5-formylbenzoic acid have been prepared.
Volume 25 Issue 4 April 1947 pp 345-350
Coumarins have been prepared from ethyl-β-resorcylate and resacetophenone by condensing them with cylic β-ketonic esters like ethyl cyclohexanone-2-carboxylate, ethyl cyclo-pentanone-2-carboxylate and ethyl-4-methyl-cyclopentanone-2-carboxylate in presence of 73 per cent. sulphurie acid, phosphorous oxychloride and anhydrous aluminium chloride as condensing agents. Only 7-hydroxy coumarins were obtained in the case of methyl β-resorcylate, while resacetophenone gave 7-hydroxy-coumarins in presence of phosphorous oxychloride, but 5-hydroxy coumarins with aluminium chloride.
Volume 29 Issue 4 April 1949 pp 227-230
Parekh and Shah5 carried out the Pechmann condensation of 4-nitroresorcinol and obtained 5-hydroxy-6-nitrocoumarin derivative. The condensation occurred in the γ-position thus showing the existence of chelation in 4-nitroresorcinol. In the present case, Gattermann reaction has been carried out on 4-nitroresorcinol, when 3-nitro-γ-resorcylaldehyde was obtained thus giving further support to the previous observation. 2-Nitroresorcinol similarly gave 3-nitro-β-resorcylaldehyde. Both the aldehydes on Knoevenagel reaction gave the respective 5- and 7-hydroxycoumarin derivatives.
Volume 29 Issue 5 May 1949 pp 314-321
No systematic study of the nitration of chromones appears to have been carried out previously, though a few naturally occurring flavones have been nitrated. In the present work, nitration of 7-hydroxy-2-methyl-chromone and 7-hydroxyflavone and their methyl ethers has been studied. The mononitro-derivatives have been found to be 8-nitro compounds while the di-derivatives were 6∶8-dinitro products. 7-Hydroxyflavone gave also a trinitro derivative which was found to be 7-hydroxy-6 ∶ 8 ∶ 4′-trinitroflavone. The constitutions of the nitro compounds were proved by alkaline hydrolysis.
Volume 30 Issue 2 August 1949 pp 57-61
In the previous work it has been shown that metallic sodium is a better reagent for the transformation of
Volume 31 Issue 3 March 1950 pp 187-190
A new method of esterification of acids is described. In this method the esterification is carried out in a dry medium (acetone) in presence of neutral substance like sodium or potassium bicarbonate with alkyl halide or alkyl sulphate. Yields of methyl esters varying from 50–80% are obtained on esterification of
This new method has several advantages. It would be particularly useful for some acids like polyhydroxybenzoic acids in which the catalytic method cannot be used, and would be a good substitute for the diazomethane method as it is simpler and also as esters higher than methyl can be prepared, there being no chance of etherification of a hydroxyl group, if present. Good results are obtained on esterification of even small amounts of the acid.
Volume 31 Issue 4 April 1950 pp 213-223
In continuation of the previous work on ψ-substituiton in resorcinol nucleus, substitution is studied in the derivatives of orcinol which is known to show ‘abnormal’ ψ-reactivity. On Pechmann condensation with ethyl aceto-acetate methyl
Volume 34 Issue 2 August 1951 pp 77-87
Volume 34 Issue 2 August 1951 pp 88-96
Volume 34 Issue 3 September 1951 pp 173-177
Two syntheses of 2-benzylresorcinol are described. Methyl
Volume 37 Issue 6 June 1953 pp 765-773
In extension of the previous work1, 2 Friedel and Crafts acylation has been studied with 4-nitroresorcinol. 4-Nitroresorcinol on Friedel-Crafts acetylation furnished 2: 6-dihydroxy-3-nitroacetophenone along with small amounts of the known 5-nitroresacetophenone, substitution occurring mainly in the γ-position. 4-Nitroresorcinol-l-methyl ether similarly gave 2-hydroxy 3-nitro-6-methoxyacetophenone as the sole product. Similar γ-substitution was observed on Friedel-Crafts propionylation, butyrylation and benzoylation of 4-nitroresorcinol. The constitutions in all the cases have been established by comparing with the products of nitration of the corresponding 2-acylresorcinols. This observation furnishes further proof of existence of chelation in 4-nitroresorcinol resulting in the preferential substitution in the γ-position.
Volume 38 Issue 1 July 1953 pp 31-39