Pyrrole 3 - acetyl - 2 - methyl - 4 - -, ethyl ester

H-Pyrrole-2-carboxylic acid, 4-acetyl-3-ethyl-5-methyl-, ethyl ester X-ray, 4, 6, 160 <72JCS(P2)902>... 

The synthesis of pyrrolo[2,3- 7 pyridazines can be achieved by starting either with pyridazine, a tetrazine, or a pyrrole. Pyridazinone 80 reacts with bromomethyl derivatives to give poor yields of 81 <1996H(43)1863> (Equation 34), while 5-acetyl-2-methyl-4-nitro-6-phenyl-3(2//)-pyridazinone, after treatment with sarcosine ethyl ester for a brief time at room temperature, followed by acid hydrolysis afforded a good yield of 82 (70%) <1994S669>. 

Much more studied is the reaction of /8-dicarbonyl compounds with 2-amino-2-deoxyaldoses in particular, with 2-amino-2-deoxy-D-glu-cose (55), both in neutral and alkaline medium. In neutral methanol or aqueous acetone, 2-amino-2-deoxy-D-glucose reacts with 2,4-pen-tanedione to give52 54 3-acetyl-2-methyl-5-(D-arabino-tetrahydroxy-butyl)pyrrole (56a), and, with ethyl acetoacetate,55 the pyrrole 56b. Similar (tetrahydroxybutyl)pyrroles have been prepared from other /3-keto esters, such as ethyl 3-oxohexanoate, ethyl thiolacetoacetate, and diethyl 3-oxopentanedioate.53,56,56a... 

Ludwig. This compound has an empirical formula corresponding to structure (1) and shows the ultraviolet and infrared" absorptions of a pyrrole-3-carboxylic ester. Its acetylation gives a tetra-O-acetyl derivative." Oxidation with lead tetraacetate yields ethyl 5-formyl-2-methyl-pyrrole-3-carboxylate (4), identical with the compound prepared in a different way. Oxidation with potassium permanganate in alkaline solution at low temperature yields 3-(ethoxycarbonyl)-2-methylpyrrole-5-carboxylic acid (7) which can be transformed " into the diethyl ester (8), identical... 

---