ethyl 3-hydroxy-4,5-dimethyl-1H-pyrrole-2-carboxylate

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: Using the method described in Example X, 18.3 g of 3-hydroxy-4,5-dimethyl-pyrrole-2-carboxylic acid ethyl ester, 20.5 g of 1,2-bromochloroethane and 18 g of anhydrous potassium carbonate give 10 g of 1-(2-carboethoxy-4,5-dimethyl-pyrrol-3-oxy)-2-chloroethane, of melting point 81°-83° C.

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: 100 g of 2-carboethoxy-3-hydroxy-4,5-dimethylpyrrole, 150 g of epibromohydrin and 152 g of dry potassium carbonate in 500 ml of acetone are refluxed for 16 hours. When it has cooled, the entire reaction mixture is poured into 3 liters of ice water, the batch is extracted with ether and the combined extracts are washed with 2 N sodium hydroxide solution and water and dried over sodium sulfate. The evaporation residue which remains after distilling off the ether and the excess epibromohydrin is extracted with heptane. 122 g of 1-(2-carboethoxy-4,5-dimethyl-pyrrol-3-oxy)-2,3-epoxypropane, of melting point 70°-71° C., are obtained. When it has cooled the entire reaction mixture the batch is extracted with ether the combined extracts are washed with 2 N sodium hydroxide solution and water dried over sodium sulfate after distilling off the ether the excess epibromohydrin is extracted with heptane

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: Using the method described in Example 1, 35 g of sodium in 1.5 liters of ethanol, and 264 g of 3-(ethoxycarbonylmethylamino)-2-methylcrotonic acid ethyl ester in 400 ml of ethanol give 165 g of 3-hydroxy-4,5-dimethyl-pyrrole-2-carboxylic acid ethyl ester, of melting point 111°-113° C.