N-methyl-2-pyrrolidinone

Methyl-3-heptanone Methylhydrazine Metolachlor Methyl mercaptan Methyl parathion Methyl phenol N-Methyl-2-pyrrolidinone Methyl tert-butyl ether Mevinphos ... 

The relative importance of the hafide anion - HO - Cell interactions can be inferred from application of the Taft-Kamlet-Abboud equation to the UV-Vis absorbance data of solvatochromic probes, dissolved in cellulose solutions in different solvent systems, including LiCl/DMAc and LiCl/N-methyl-2-pyrrolidinone [96]. According to this equation, the microscopic polarity measured by the indicator, Ej (indicator), in kcalmol is correlated with the properties of the solvents by Eq. 1 ... 

N-Methyl-2-pyrrolidinone 2 KHSO5 KHSO4 K2SO4 Polymeric backbone Pyridinium chlorochromate Pyridinium dichromate Polyethylene glycol... 

Preparation of MVE-methotrexate-y-hydrazide. MVE copolymer (200 mg) was dissolved in 4 mL of N-methyl-2-pyrrolidinone. Triethylamine (0.38 mL) was added to the MVE solution, followed by methotrexate-y-hydrazide (262 mg) in 4.5 ml of N-methyl-2-pyrrolidinone. The reaction solution was stirred at room temperature for three days. 

GC analysis for methanol, 1-propanol, 1-butanol, pyrrolidine, N-methylpyrrolidine, 2-pynolidinone, N-methyl-2-pyrrolidinone, gamma-butrolactone, dimethylsuccinate, and N-butyl-2-pyrrolidinone was performed with a Hewlett-Packard Model 5890 Gas Chromatograph equipped with a 30-meter, 0.53 mm I.D., 0.50-micron film, Nukol capillary column (Supelco, Bellefonte, PA) and a flame ionization detector (FID). 

The method described for the preparation of N-methyl-2-pyrrolidinethione is very similar to that of Peak and Stansfield 2 for the preparation of 4-thioacetylmorpholine. N-Methyl-2-pyrrolidinethione has also been prepared by the reaction of 2-chloro-N-methyl-A1-pyrrolinium chloride with hydrogen sulfide [yield 83% b.p. 144-145° (15 mm.)]3 and by heating N-methyl-2-pyrrolidinone with 2 equivalents of phosphorus pentasulfide in xylene [yield not reported b.p. 125-132° (10 mm.)].4 General procedures for the preparation of N,N-disubstituted thioamides have been reviewed.5, 6... 

Selective 1,4-reduction of unsaturated aldehydes and ketones by 6 occurs smoothly in THF between —25 °C and room temperature within a few hours (Eq. 5.7). Particularly noteworthy is the realization that phosphines are noticeably absent from the reaction medium. The analogous combination of CuCl/BusSnH in N-methyl-2-pyrrolidinone (NMP) or DMF does not behave identically [22], failing to react with the hindered substrate isophorone, whereas a 72% yield of the corresponding reduced ketone is formed with reagents XCu(H)Li/Bu3SnH. Nonetheless, a form of CuH is being generated in this more polar medium, effectively utilized by Tanaka to arrive at 3-norcephalosporin 8 upon reaction with allenic ester 7 (Scheme 5.3). 

The rhodium catalyst currently used for this step utilizes a monosulfonated phosphine ligand, dissolved N-methyl-2-pyrrolidinone (NMP).(6) This catalyst system has shown adequate activity and stability. More importantly, it enables product-catalyst phase separation. (7)... 

Solvents that have been less extensively used are N-methyl-2-pyrrolidinone and hexamethylphosphoric triamide.183 The author of this article183 also discussed the purification of chlorotrimethylsilane, and the anomalous results that may be obtained from the use of impure reagent have been commented on in the case of analyses of pentaerythritol.184 The various methods available for the bulk purification of methyl sulfoxide have been reviewed,185 and a symposium on this compound reviewed its use as a solvent in selected reactions.186... 

According to the hard and soft acids and bases (HSAB) concept, hard acids tend to interact strongly with hard bases, while soft acids tend to interact strongly with soft bases. The HSAB concept applies also to solute-solvent interactions. Figure 2.5 shows the polarographic half-wave potentials of metal ions in N-methyl-2-pyrrolidinone (NMP) and N-methyl-2-thiopyrrolidinone (NMTP) [13]. Here, we can compare the half-wave potentials in the two solvents, because they are referred to the half-wave potential of the bis(biphenyl)chromium(l)/(0) couple,... 

Decarbonylation of aldoses.2 Although this rhodium complex has been known since 1968 to effect decarbonylation of aldehydes, it has been used for decarbonylation of sugars only recently, probably for lack of a compatible solvent. Actually, this reaction when carried out in N-methyl-2-pyrrolidinone (NMP) at 110-130° is extremely useful in the case of simple aldoses, which are converted to the lower alditol with formation of carbonylchlorobis(triphenylphosphine)rhodium(I). The yields are 75-95%. This method of degradation has the further advantage that protecting groups are not necessary. Deoxyaldoses, particularly 2-deoxyaldoses, are decar-bonylated in 75-99% yield. A disadvantage of this reaction is that a full equivalent of the complex is required. 

Conditions Entries 1-3 To a mixture of ArCHO (0.5 mmol), 4-methoxyaniline (0.5 mmol), and (S)-proline (0.15 mmol) in DMF (3 mL), donor aldehyde (5.0 mmol) in DMF (2 mL) was slowly added (0.2 mL min-1) at —20 °C. The mixture was stirred at the same temperature for 4-10 h. The mixture was diluted with Et20 and reduction performed by addition of NaBH4 [71b]. Entries 4 and 5 After stirring a solution of ArCHO (1.0 mmol), 4-methoxyaniline (1.1 mmol), and (S)-proline (0.1 mmol) in N-methyl-2-pyrrolidinone (1.0 mL) for 2 h at rt, propionaldehyde (3.0 mmol) was added to the mixture at -20 °C, and stirring was continued for 20 h at the same temperature. The reaction was worked-up and reduction with NaBH4 performed without purification [82]. 

Method B After stirring a solution of ArCHO (1.0 mmol), 4-methoxyaniline (1.1 mmol), and (S)-proline (0.1 mmol) in N-methyl-2-pyrrolidinone (1.0 mL) for 2 h at r.t., propionaldehyde (3.0 mmol) was added to the mixture at — 20 °C, and stirring continued for 20 h at the same temperature. The reaction was worked-up and reduction with NaBH4 was performed without purification. 

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