Pyrrole, 2,4 dimethyl 3 ethyl

Pyrrole, 2,4-dimethyl-3-acetyl-5-CARBETHOXY-, 21, 68 Pyrrole, 2,4-dimethyl-3-ethyl-, 21,... 

Pyrrole oxidizes in air to red or black pigments of uncertain composition. More usehil is the preparation of 2-oxo-A -pyrrolines, which is best carried out by oxidation of the appropriate pyrrole with in pyridine (37), eg, 3,5-dimethyl-ethyl-3-pyrrolin-2-one [4030-24-4] from... 

Pyrrole-2-carboxylic acid, 4,5-dimethyl-ethyl ester formylation, 4, 217 Pyrrole-2-carboxylic acid, 3-hydroxy-... 

Pyrrole-3-carboxylic acid, l-benzoyl-5-bromo-2,4-dimethyl-ethyl ester chlorination, 4, 271... 

Pyrone, 3-hydroxy-2-methyl Sd (roasted) Pyrrole, 1-5-dimethyl Sd (roasted) Pyrrole, 1-ethyl Sd (roasted) ... 

Pyrrole (General) Ethyl 2,5-dimethyl-lH-pyrrole-3-carboxylate ... 

The synthesis of dipeptidyl peptidase-IV (DPP4) inhibitor, Saxagliptin 32 (Figure 11.8) required (5S)-5-aminocarbonyl-4,5-dihydro-lH-pyrrole-l-carboxylicacid,l-( 1,1-dimethyl ethyl)-ester 33 [82-84], Direct chemical am-monolyses were hindered by the requirement for aggressive reaction conditions, which resulted in unacceptable levels of amide racemization and side-product... 

The preparation of 2 4-dimethyl-3 5-dicarbethoxypyrrole (II) is an example of the Knorr synthesis of pyrrole derivatives, involving the reaction of an -aminoketone (or a derivative thereof) with a reactive methylene ketone (or a derivative thereof). The stages In the present synthesis from ethyl acetoacetate (I) may be represented as follows ... 

Pyrrole-2-carboxamide, N,N-dimethyl-conformation, 4, 194 Pyrrole-3-carboxamide, N,N-dimethyl-conformation, 4, 194 Pyrrolecarboxamides synthesis, 4, 242 Pyrrole-2-carboxamides synthesis, 4, 148, 360 Pyrrolecarboxylhydrazides Curtius degradation, 4, 362 Pyrrole-2-carboxylic acid, l-benzyl-3-hydroxy-ethyl ester... 

In a i-l. round-bottomed, three-necked flask fitted with an efficient reflux condenser, liquid-sealed stirrer, and dropping funnel is placed t3 g. (0.53 gram atom) of magnesium turnings. A few cubic centimeters of a solution of 60 g. (41.4 cc., 0.55 mole) of pure ethyl bromide in 50 cc. of absolute ether is added and the stirrer started (Note i). When the bromide begins to react 200 cc. of absolute ether is added, and then the balance of the bromide solution is run in as fast as the refluxing permits (about one-half hour). After allowing fifteen minutes for the completion of the reaction, a solution of 40 g. (0.42 mole) of 2,4-dimethyl-pyrrole (Org. Syn. 15, 20) in 100 cc. of absolute ether is added in the course of twenty minutes (Note 2) and the mixture is refluxed for one-half hour on the steam bath. 

The most convenient laboratory method for the preparation of 2,4-dimethyl-5-carbethoxypyrrole is that given above. A cheaper method of obtaining large quantities consists in the partial hydrolysis of 2,4-dimethyl-3,5-dicarbethoxypyrrole with sulfuric acid, followed by decarboxylation. The ester has been obtained also by the alcoholysis of 5-trichloroaceto-2,4-dimethyl-pyrrole in the presence of sodium ethylate. The free acid has been obtained fronii-[2,4-dimethylpyrrole-5]-2,4-dimethylpyrrole-5-carboxylic acid and from 2,4-dimethylpyrrole-5-aldehyde. ... 

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