1-methylpyrrole-2,5-dione

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:

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: An 86 g portion of m-bromoaniline was dissolved in a mixture of 150 ml of 12N hydrochloric acid and 100 ml of water, cooled in an ice-salt bath. A 100 g portion of ice was added, followed by a solution of 34.5 g of sodium nitrite in 80 ml of water, added dropwise over 45 minutes. A solution of 55.5 g of N-methylmaleimide and 12.5 g of cupric chloride dihydrate in 700 ml of acetone was then added slowly over 40 minutes, while maintaining the temperature between 10° C. and 15° C. A 56 g portion of sodium bicarbonate was added to achieve pH 2.6. The mixture was allowed to stand for 72 hours, and the resultant oil was extracted with 300 ml of chloroform. This solution was filtered through magnesium silicate. The filtrate was evaporated in vacuo and gave a crude crystalline product. The crude product was combined with 58 ml of 2,6-lutidine and 600 ml of isopropyl alcohol and heated on a steam bath for 1/2 hour. The reaction mixture was poured into 1.25 liters of water and allowed to stand at room temperature for 18 hours. The crystalline product was collected, washed with water, air dried, and then recrystallized from 500 ml of acetonitrile to give 62.5 g of 2-(m-bromophenyl)-N-methylmaleimide. cooled in an ice-salt bath A 100 g portion of ice was added added dropwise over 45 minutes while maintaining the temperature between 10° C. and 15° C the resultant oil was extracted with 300 ml of chloroform This solution was filtered through magnesium silicate The filtrate was evaporated in vacuo gave a crude crystalline product heated on a steam bath for 1/2 hour to stand at room temperature for 18 hours The crystalline product was collected washed with water, air dried recrystallized from 500 ml of acetonitrile

Conditions: temp:5.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A 30.9 g amount of 3,4-methylenedioxyaniline hydrochloride was dissolved in 90 ml of water and 40 ml of concentrated hydrochloric acid. The solution was cooled to 5° C. in an ice-salt bath and a solution of 12.3 g of sodium nitrite in 35 ml of water was added dropwise to the reaction mixture over a 25 minute period. A solution of 20.0 g of N-methylmaleimide and 2.4 g of cupric chloride in 150 ml of acetone was added to the reaction mixture portionwise with stirring. The reaction mixture temperature was maintained at 3° C. and the pH was adjusted to 3.2 by the addition of about 30 g of sodium bicarbonate. After standing at room temperature for 16 hours the mixture was filtered to collect a black solid. The solid was dried. Then the solid was dissolved in 500 ml of isopropanol containing 19.5 g of 2,6-lutidine. The mixture was heated to boiling and filtered hot to collect 4.8 g of isoluble material. The filtrate was cooled and an additional 2.6 g of precipitate was collected. This filtrate was reduced in volume to 200 ml and cooled and filtered to collect 2.7 g more of precipitate. The final filtrate was diluted with water and filtered to collect 0.9 g of additional material. The precipitates were combined and subjected to preparative liquid chromatography using a silica gel column and ethyl acetate:hexane (1:1) as eluent. The second cut, 0.6 g was recrystallized from ethyl acetate to give 0.1 g of 3-(1,3-benzodioxol-5-yl)-1-methyl-1H-pyrrole-2,5-dione as a brown solid, mp 210°-215° C. The reaction mixture temperature was maintained at 3° C. the mixture was filtered to collect a black solid The solid was dried Then the solid was dissolved in 500 ml of isopropanol containing 19.5 g of 2,6-lutidine The mixture was heated filtered hot to collect 4.8 g of isoluble material The filtrate was cooled an additional 2.6 g of precipitate was collected cooled filtered to collect 2.7 g more of precipitate The final filtrate was diluted with water filtered to collect 0.9 g of additional material The second cut, 0.6 g was recrystallized from ethyl acetate

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

Procedure: A 100 g portion of N-methylmaleimide was reacted with 126.2 g of p-nitroaniline as described in Example 6, giving 78 g of 2-(p-nitrophenyl)-N-methylmaleimide.

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

Procedure: A 162 g portion of 3,4-dichloroaniline was reacted with 111 g of N-methylmaleimide as described in Example 6, giving 112 g of 2-(3,4-dichlorophenyl)-N-methylmaleimide.

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

Procedure: An 80.6 g portion of 3-aminobenzotrifluoride was reacted with 55.6 g of N-methylmaleimide as described in Example 6, giving 2-(m-trifluoromethylphenyl)-N-methylmaleimide.