2-Pyrrolidinecarboxylic acid, 1-

The addition of a-(acylamino) esters to 3-aryl-2-propenoates, with sodium ethoxide in ethanol or sodium hydride in benzene as base, is a frequently ultilized procedure9-" A The initial Michael adducts cyclize to 3-aryl-5-oxo-2-pyrrolidinecarboxylic acids with modest to high trans diastereoselectivities 10°. 

Oxidation of cyclic secondary amines such as pyrrolidine (351) and piperidine (353) with iodosobenzene in water leads to lactams 352 and 354, respectively (88TL6913, 88TL6917) (Scheme 90). Similar oxidation of 2-piperidinecarboxylic acid and 2-pyrrolidinecarboxylic acid is accompanied by decarboxylation. Cyclic tertiary amines 355, 357, and 359 (Eq. 48) are likewise oxidized to the corresponding lactams. Other examples include phencyclidine (360) to A-(l-phenylcyclohexyl)piperidone (361), N-(cyanocyclohexyl)piperidine (362) to A-(l-cyanocyclohexyl)piperidone (363) (Scheme 91), and 1,2,3,4-tetrahydroisoquinoline to 1,2,3,4-tetrahy-droisoquinolinone (Eq. 49). 

Birch Reduction—Alkylation of Derivatives of l-Aroyl-2-pyrrolidinemethanol and l-Aroyl-2-pyrrolidinecarboxylic Acids... 

The combined Birch reduction alkylation of chiral, enantiomerically pure aroyl amides of 2-pyrrolidinemethanol (prolinol) or 2-pyrrolidinecarboxylic acid (proline) gives chiral, non-racemic, 1,1-disubstituted 2,5-cyclohexadienes 1 or 2-cyclohexenes 2, respectively, in high diastereomeric ratios. These reactions are useful for the preparation of valuable chiral synthetic intermediates 3 25 29-31-36. 

Acylation of 2-pyrrolidinemethanol with benzoyl or substituted benzoyl chlorides gives chiral l-aroyl-2-pyrrolidinemethanols while condensation of 2-pyrrolidinecarboxylic acid with 2 H-3,l-benzoxazinc-2,4-(l 7/)-diones results in pyrrolobenzodiazepinediones25. 

A mixture of 56.5 mmol of the 2/7-3,l-benzoxazine-2,4(l//)-dione 1 (R1 = H, CH3), 6.53 g (56.5 mmol) of pyridine hydrochloride and 7.15 g (62.2 mmol) of (S )-2-pyrrolidinecarboxylic acid is refluxed in pyridine for 6 h. After cooling and evaporation of the pyridine in vacuo, the resulting semisolid is partitioned between water and CHC13. The organic extract is washed with two 15-mL portions of 1M aq hydrochloric acid, followed by brine, and then dried over MgS04, filtered and concentrated to give a solid which, when triturated with ethyl acetate, gives the analytically pure product. 

Other physical phenomena that may be associated, at least partially, with complex formation are the effect of a salt on the viscosity of aqueous solutions of a sugar and the effect of carbohydrates on the electrical conductivity of aqueous solutions of electrolytes. Measurements have been made of the increase in viscosity of aqueous sucrose solutions caused by the presence of potassium acetate, potassium chloride, potassium oxalate, and the potassium and calcium salt of 5-oxo-2-pyrrolidinecarboxylic acid.81 Potassium acetate has a greater effect than potassium chloride, and calcium ion is more effective than potassium ion. Conductivities of 0.01-0.05 N aqueous solutions of potassium chloride, sodium chloride, potassium sulfate, sodium sulfate, sodium carbonate, potassium bicarbonate, potassium hydroxide, and sodium hydroxide, ammonium hydroxide, and calcium sulfate, in both the presence and absence of sucrose, have been determined by Selix.88 At a sucrose concentration of 15° Brix (15.9 g. of sucrose/100 ml. of solution), an increase of 1° Brix in sucrose causes a 4% decrease in conductivity. Landt and Bodea88 studied dilute aqueous solutions of potassium chloride, sodium chloride, barium chloride, and tetra-... 

Oxo-2-pyrrolidinecarboxylic acids 2-[((Phenylamino)carbonyl)oxy]propanoic acid 1-Phenylethanesulfonic acid... 

PYRROLIDINECARBOXYLIC ACID see PiMH900 PYRROUDINE, l-METHYL-2-(3-PYRIDYL)-, SULFATE see NDR500... 

The chiral amino acid ionic liquid, l-ethyl-3-methylimidazolium (S)-2-pyrrolidinecarboxylic acid salt [emim][Pro] (1), is synthesized in 70% overall yield by the following procedure (Fig. 12.56). 

Pyrrolidinecarboxylic acid, l-(trifluoro-acetyl)-, (S)- [30163-31-6], 56, 125 1,2-Pyrrolidinedicarboxylic acid, 3-hydroxy-, l-(phenylmethyl) ester [57621-07-5], 55, 89... 

Hydroxy-L-proline. Hyp L(-hydroxyproline Irans-hydroxyproline 4-hydroxy-2-pyrrolidinecarboxylic acid. CjHjNOj mol wt 131.13. C 45.79%, H 6.92%, N 10.68%, O 36.60%. An amino acid classified as nonessential with respect to its growth effect in rats. Constituent of collagen, q.v. Isolt) from gelatin h yd roly rates E. Fischer, Ber. 35, 2660 (1902) Klabunde, J. Biol Chem. 90, 293 (1931). 

For pyrrolidines with more substituents on the five-membered ring, proline is not a convenient starting material. For pyrrolidines containing different substituents in positions 2 and 5, the enantiomers of glutamic acid are inexpensive starting materials. Thus, the esters of D- and L-pyroglutamic acid [(7 )- and (,S )-5-oxo-2-pyrrolidinecarboxylic acid] are readily obtained in a one-pot procedure from (R)- or (S)-glutamic acid ... 

Propanoic acid, 3-(methylnitrosamino)-, methyl ester Propanoic acid, 2-(methylnitrosamino)-3-phenyl-2-Pyrrolidinecarboxylic acid, 1-nitroso-, methyl ester... 

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