Water → Methyl 4-(2,3-dichlorophenyl)-1H-pyrrole-3-carboxylate

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Reaction Steps

With stirring, 20 g of methyl α-methylcarbonyl-2,3-dichlorocinnamate are added at 0° C. to a 22 % by weight solution of (p-tolylsulfonyl)methyl isocyanide prepared according to Example P1 (a). Then 26.3 g of a 30% solution of sodium methylate in methanol are added dropwise over 2 hours. The mixture is stirred for 2 hours and then 35 ml of water are added dropwise. The reaction mixture is concentrated at +50° C. under vacuum. After addition of 70 ml of water, the reaction mixture is concentrated once more under vacuum and then filtered. The filter residue is washed with toluene and recrystallised from ethanol, affording 10.8 g (58% of theory) of 4-methoxycarbonyl-3-(2,3-dichlorophenyl)-pyrrole which melts at 200°-201° C.

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