N-Methylpyrrolidin-2-one

Decarbonylation of sugars.1 Aldoses undergo decarbonylation when treated with this organometallic in N-methylpyrrolidin-2-one (NMP) at 130°. Thus glucose is converted into arabinitol in 88% yield (equation I). 

The decarbonylation reaction is not confined to aldehydes, but also embraces those compounds that have aldehyde tautomers. Thus, both carbohydrates and allylic alcohols can be decarbonylated. When glucose is allowed to react with fra/ 5-[RhCl(CO)(PPh3)2] in N-methylpyrrolidin-2-one, decarbonylation occurs and arabinitol is formed with retention of configuration. The decarbonylation of fructose to arabinitol is complicated by the simultaneous dehydration to furfuryl alcohol, which is the major product. Analogous reactions occur with lower carbohydrates in the limit, glycolaldehyde is decarbonylated to methanol. Aldose derivatives can also be converted to their C i analogues, but the yields are only about half of those obtained with the parent aldoses. Disaccharides usually give better yields. 

EG. BordweU, J.C. Branca, D.L. Hughes, and W.N. Olmstead, Equilibria involving organic anions in dimethyl sulfoxide and N-methylpyrrolidin-2-one Acidities, ion pairing, and hydrogen bonding, J. Org. Chem. 45 (1980), pp. 3305-3313. 

N-Methylpyrrolidin-2-one (Figure 3.2). Data are available for 303 K (Marcus 2001) and the mixtures are nearly ideal. Above Xs = 0.2, mutual association of the components is preferred and water-water interactions are disfavored. These aqueous mixtures resemble in this respect the ethanolamine mixtures. 

Aldoses are smoothly decarbonylated by chlorotrisCtriphenylphos-phine)rhodium in N-methylpyrrolidin-2-one giving the next lower... 

Sodium trifluoroacetate, in the presence of copper(l) iodide, was also used as trifluoromethyl source to replace halogen by trifluoromelhyl group in the thiophene system. Sodium trifluoroacetate was decarboxylated, forming fluoroform, when heated alone in aqueous N-methylpyrrolidin-2-one. The addition of copper(l) iodide increased the rate of decarboxylation dramatically. The mechanism of this process was explored and an intermediate [CFsCul] was proposed. Introduction of higher perfluoroalkyl groups from their corresponding sodium perfluoroalkane carboxyl-ates was also shown to be possible [58],... 

Dimethyl and diethyl (l-methylpyrrolidin-2-ylidene)malonates (e.g., Scheme 38,467, n = 0, R = R1 = Me, Et R2 = H R4 = Me) and diethyl (l-methyl-l,2-dihydroquinolin-2-ylidene)malonate were obtained in 30-52% yields when l-methylpyrrolidin-2-one and 1-methyl-1,2-dihydroquinolin-2-one were first reacted with phosgene and then with dialkyl malonates in the presence of triethylamine in benzene at 60°C (61CB2278 69JA6683). 

Non-metal catalyzed aziridinations have also been reported. These methods are often more broadly applicable than the metal-catalyzed methods. The use of A -methylpyrrolidine-2-one hydrotribromide (MPHT) and chloramine-T is an effective route for the synthesis of N-tosyl aziridines <06MI16>. The aziridination of olefins using f-BuOI and sulfonamides appears to be a general method for aziridination <06CC3337>. The t-BuOI is prepared in situ from t-BuOCl and Nal. This is a broadly applicable method in that a wide variety of sulfonamides (tosyl, nosyl, SES) can be used with roughly equivalent yields. 

Relative and quantitative acidities in many other solvents have been measured. These solvents have included diethyl ether [396], benzene [397] isopropyl alcohol [521,522], n-hexane, heptane [523,524], ENREF [536] /V,A-dimethylformamide (DMF) [525], methanol [522,526,527], ethanol [522,526], terf-butanol [522], cyclohexylamine [528], glacial acetic acid [529], and A-methylpyrrolidin-2-one [530]. 

Replacement of dipolar aprotic solvents such as lV-methylpyrrolidin-2-one (NMP), N,N-dimethylformamide (DMF), and lV,lV-dimethylacetamide (DMAc)... 

Methyl-2-pyrrolidone see l-Methylpyrrolidin-2-one N-Methylpyrrolidone see l-Methylpyrrolidin-2-one alpha.-Methylstyrene see Isopropenylbenzene Methyl sulfoxide see Dimethyl sulfoxide... 

Nitrous oxide see Dinitrogen oxide NM see Nitromethane NMF see N-Methylmethanamide NMP see l-Methylpyrrolidin-2-one l,l)l)2,2,3,3,4,4-Nonafluorohexane... 

A selenium-assisted carbonylation reaction has been developed which gives 1,3-dihydro-2/f-imidazo[4,5-b]pyridin-2-ones (314) in an excellent yield (Scheme 30) <87BCJ1793>. Heating 2,3-diaminopyridine (312) with CO and an equimolar amount of selenium in the presence of N-methylpyrrolidine, proceeds through a selenolcarbonate intermediate (313) which then cyclizes to the desired product (314). 

Treatment of 3,4-diaminopyridine (350) with carbon monoxide in the presence of selenium in N-methylpyrrolidine gives imidazo[4,5-c]pyridin-2-one (351) (96%) (Equation (28)) <87BCJ1793>. The selenium must be present in a stoichiometric or excess amount, or an acyclic urea formed via an intermolecular condensation of two 3,4-diaminopyridine moieties is the major product. 

Pinner s formulation of nicotine received support from the discovery that the nicotyrine (3 -pyridyl-N-methyl-2-pyrrole) formed by the oxidation of nicotine with silver oxide is accompanied by a small quantity of N-methylpyrrolidine (357), and from the methylation of nicotine which gives rise to two isomeric quaternary methiodides (358). One of these, nicotine isomethiodide, yields a quaternary hydroxide which on oxidation with potassium permanganate produces trigonelline, the methylbetaine of nicotinic acid. Nicotine isomethiodide, therefore, has a quaternary pyridine nitrogen, C6H4N CH3I C4H7N CH3 while nicotine methiodide has... 

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