2,4-Dimethylpyrrole

Chemical Properties

clear light yellow to light yellow-orange liquid

Uses

2,4-Dimethylpyrrole may be used in the synthesis of the following:

• 2,5-bis(2′,4′-dimethyl-5′-pyrryl)p-benzoquinone
• boron dipyrromethene (BODIPY) dyes
• 2,4-dimethyl-6-methoxyprodigiosene

Uses

2,4-Dimethylpyrrole is a substituted pyrrole. Its synthesis by using ethyl acetoacetate as starting material has been reported. Its basicity has been evaluated from UV spectral data.Its photodecomposition on irradiation has been reported to afford H2, CH4, C2H6 and polymeric products.

2,4-Dimethylpyrrole may be used in the synthesis of the following:
2,5-bis(2′,4′-dimethyl-5′-pyrryl)p-benzoquinone.
boron dipyrromethene (BODIPY) dyes.
2,4-dimethyl-6-methoxyprodigiosene.

Synthesis Reference(s)

Synthesis, p. 1585, 2000 DOI: 10.1055/s-2000-7618

General Description

2,4-Dimethylpyrrole is a substituted pyrrole. Its synthesis by using ethyl acetoacetate as starting material has been reported. Its basicity has been evaluated from UV spectral data. Its photodecomposition on irradiation has been reported to afford H₂, CH₄, C₂H₆ and polymeric products.

Synthesis

420 g (2.0 mol) of 2,4-dimethyl-3,5-bismethoxycarbonylpyrrole were suspended in 1200 g of 20% strength sodium hydroxide solution, and the mixture was heated. The solid gradually passed into solution during this process. At 92° C. gas had started to evolve vigorously; some of the dicarboxylic acid was decarboxylated in the process. The methanol formed during the hydrolysis was distilled off continuously until essentially only water was passing over. The mixture which remained was then neutralized with 250 g of 50% strength sulfuric acid (pH about 7.5) and heated to boiling at the reflux condenser with water separator. The 2,4-dimethylpyrrole separated out as a yellow upper phase over the course of a few hours. The aqueous phase was continuously recycled into the boiling mixture. A total of 152.5 g of organic phase was obtained. This comprised 8.1% of water, the remainder consisted of 99.1% of 2,4-dimethylpyrrole, determined as area percentages by gas chromatography using a flame ionization detector. This corresponded to 138.9 g of 2,4-dimethylpyrrole (73% of theory).