• DR R R PANDEY

P- Toluic acid [I] was taken as the starting material. This compound underwent sulphonation with concentrated sulphuric acid and fused with potassium hydroxide to 3 - hydroxy -3 - methylbenzoic acid [II]. The compound [II] underwent methylation with dimethyl sulphate and NaoH ( aq) under reflux to give 3- methoxy -4 methylbenzoic acid [III]. Experiment with a homogeneous solution of [III], Chloralhydrate and H2SO4 (conc.) afforded 6- methoxy-5-methyl-3- trichlorophthalide [IV] which was reduced with Zn - dust and glacial acetic acid to furnish 2- (ββ-Dichloroethyl)-4- methyl-5- methoxy benzoic acid [V]. The compound [V] was heated with H2SO4 (conc.) On water bath till no more hydrochloric gas had evolved then 2- carboxy -4 methoxy -5- methylphenylacetic acid [VI] was furnished . The compound [VI] underwent cyclization with acetic anhydride and pyridine in dry ether to give 4- acetyl - 7- methoxy -6- methylisochroman -1,3- dione [VII]. The dione underwent rearrangement with 80% H2SO4 to give a mixture of 4-carboxy -7-methoxy-3,6-dimethylisocoumarin [VIII]. The [VIII]-carboxy compound was separated from [VIII] by treatment with NaHCO3 solution by acidification. Subsequent decarboxylation of this carboxy compound yielded 7- methoxy -3,6 dimethylisocoumarin [IX]. The present work embodied in the dissertation of focuses on the new synthesis of 3,4 - dihydroxy - 7 methoxy -3,6- dimethyl isocoumarin [XI] and pinacol pinacolone rearrangement of [XI] by heating with KBro3 / H2SO4 (dil) yielded the 7- methoxy -3,6 dimethylisocoumarin -1 ,4 - dione [XII].

"Synthesis of 3,4 , - dihydroxy -7- methoxy -3,6- dimethyl isocoumarin and studies of Pinacol - Pinacolone rearrangement upon them.", International Journal of Emerging Technologies and Innovative Research (www.jetir.org), ISSN:2349-5162, Vol.8, Issue 8, page no.d525-d534, August-2021, Available :http://www.jetir.org/papers/JETIR2108437.pdf

"Synthesis of 3,4 , - dihydroxy -7- methoxy -3,6- dimethyl isocoumarin and studies of Pinacol - Pinacolone rearrangement upon them.", International Journal of Emerging Technologies and Innovative Research (www.jetir.org | UGC and issn Approved), ISSN:2349-5162, Vol.8, Issue 8, page no. ppd525-d534, August-2021, Available at : http://www.jetir.org/papers/JETIR2108437.pdf