Valin Hydrochlorid

C25H30N2O3 137863-90-2) see Valsartan methyl L-valinate hydrochloride (C(jHi4ClN02 6306-52-1) see Valsartan methyl vinyl ketone... 

DLSERN11. D,L-Serine (neutron study) (C3H7N03). Frey MN, Lehmann MS, Koetzle TF, Hamilton WC (1973) Acta Crystallogr, Sect B 29 876 DLTYRS. D,L-iyrosine (CgHnNO. Mostad A, Romming C (1973) Acta Chem Scand 27 401 DLVALC. D,L-Valine hydrochloride (C5H12NO, Cl-). Di Blasio B, Napolitano G, Pedone C... 

VALEHC10. L-Valine hydrochloride (C5H12N02+, Cl"). Ando O, Ashida T, Sasada Y, Kakudo M (1967) Acta Crystallogr 23 172... 

VALEHC11. LrValine hydrochloride (neutron study) (CjH NO, Cl-). Koetzle TF, Golic L, Lehmann MS, Verbist JJ, Hamilton WC (1974) J Chem Phys 60 4690 VALHCL10. L-Valine hydrochloride monohydrate (CsH NO, Cl-, H20). Rao ST (1969) Z Kristallogr 128 339... 

Sketch the pH curve for the titration of 1 mole of glutamylseryl glutamyl valine hydrochloride. 

Gervais et al. also studied selected amino acid hydrochlorides, using i4n, i7q 35( j SSNMR spectroscopy in 2005. EFG and isotropic chemical shift data were reported for glycine hydrochloride, L-valine hydrochloride and... 

FIGURE 1.18 2-AI koxy-5(4/7)-oxazol ones as intermediates in reactions of IV-alkoxycarbo-nylamino acids.22 After removal of the symmetrical anhydride from a reaction mixture containing Boc-valine and ethyl-(3-dimethylaminopropyl)-carbodiimide hydrochloride, the filtrate contained a novel activated form of Boc-valine (20% yield) that was established to be the 2-alkoxy-5(4H)-oxazolone. Slow addition of Boc-valine to ethyl-(3-dimethylamino-propyl)-carbodiimide hydrochloride in dilute solution gave a 55% yield. Petrol = petroleum ether, bp 40-60°. 

The iminium salt 132, generated from benzylamine hydrochloride and aqueous formaldehyde, reacts with cyclopentadiene during 3 h at room temperature to give, after basification, the cycloadduct 133 in nearly quantitative yield (equation 70). Other examples of this reaction are shown in equations 71-75. The separable diastereomers 134 and 135 are formed in the ratio 4 1 from cyclopentadiene, (—)-a-methylbenzylamine hydrochloride and aqueous formaldehyde in a combined yield of 86% (equation 75)62. Hydrochlorides 136 of methyl esters of natural amino acids [(S )-valine, (S )-isoleucine] react with cyclopentadiene and formaldehyde in aqueous THF to produce mixtures of the diastereomers 137 and 138, in which the former predominate (equation 76)63. 

The central point of Evans s methodology is the induction of a 7t-enantiotopic facial differentiation through a conformationally rigid highly ordered transition state. Since the dialkylboron enolates of AT-acyl-2-oxazolidinones exhibit excellent syn-diastereoselectivity syn.anti >97 3) when reacted with a variety of aldehydes, Evans [14] studied the aldol condensation with the chiral equivalents 32 and 38. which are synthesised from fS)-valine (35) and the hydrochloride of (15, 2R)-norephedrine (36) (Scheme 9.11), respectively, and presently are commercially available. 

The compounds investigated were the amino acids L-isoleucine, L-leucine, L-valine, and L-a-amino butyric acid. These compounds have similar molecular structures, as shown in Figure 2, and will be referred to throughout the present work as L-Ile, L-Leu, L-Val, and L-a-ABA. Where there is little likelihood of confusion, the designation L- will be omitted. Operations examined included crystallization of He through the addition of hydrochloric acid and through cooling. Under acidic conditions He crystallizes as a hydrochloride salt while in the vicinity of the isoelectric point (pH 5.2) it crystallizes as the neutral zwitterionic... 

High stereoselectivities (94-100 %) are attained in the reduction of aromatic ketones by use of a new chiral borane complex with (S)-2-amino-3-methyl-l,l-diphenylbutan-l-ol,(S-68) readily prepared in two steps from (S)-valine, in an experimentally convenient procedure961. (S)-Valine methyl ester hydrochloride was converted with excess of phenylmagnesium bromide into (S-68). The same treatment of (R)-valine gave (R-68). In a typical asymmetric reduction the reagent, prepared from (S-68) and borane, and the ketone (69) in tetrahydrofuran were kept at 30 °C for some hours. The corresponding alcohols were obtained in high optical purity. (S-68) could be recovered to more than 80% without racemization 96). 

As actually carried out, the aldehyde was converted to the amino nitrile by treatment with an aqueous solution containing ammonium chloride and potassium cyanide. Hydrolysis was achieved in aqueous hydrochloric acid and gave valine as its hydrochloride salt in 65% overall yield. 

Valine methyl ester, (S)-, hydrochloride Benzyl chloroformate Palladium hydroxide... 

To a 5 L 3-neck round bottom flask was added the crude carbonylbenzyloxy-3-aminopropanal (115 g, 0.555 mol) followed by addition of water (400 mL) and methanol (1600 mL). The reaction mixture was maintained at 25°C throughout the course of the reaction. After the solution became homogeneous. (S)-Valine methyl ester hydrochloride (90.2 g, 0.538 mol) was added in one portion followed by rapid addition of sodium acetate trihydrate (151 g, 1.11 mol) and sodium cycanoborohydride (73.2 g, 1.17 mol). The reaction mixture was allowed to stir at room temperature for 0.5 hour and was concentrated in vacuo. To this solution, saturated aq sodium bicarbonate (400 mL) was added and the mixture was extracted with isopropyl acetate (1 L). The organic layer was washed with water, dried over sodium sulfate, and concentrated to yield 150 g of crude product, which was dissolved in isopropyl acetate (300 mL) and heptane (2400 mL). Dry HCI was bubbled in and an oily solid precipitated out of solution. The liquid was decanted away from and the solid was dissolved in dichloromethane (3 L). The solution was washed with water (600 mL) and saturated aq sodium bicarbonate (600 mL) and dried over sodium sulfate. It was concentrated in vacuo to yield 105 g (59%) of N-(N-(benzyloxycarbonyl-3-amino)-propyl)valine methyl ester as a light yellow oil. 

L)-Valine methyl ester hydrochloride 2 -Cyanobiphenyl-4-carbaldehyde Sodium cyanoborohydride... 

L-Valine methyl ester hydrochloride Valine, methyl ester, hydrochloride, L-(8) L-Valine, methyl ester, hydrochloride (9) (6306-52-1)... 

In 1981, Hirao and others reported that the chiral borane-amine complex 25a, derived from (S)-prolinol and 1 equivalent of BH3 THF, enantioselec-tively reduced propiophenone to afford (R )-l -phenyl-1 -propanol (26) in 44% ee9 (Scheme 4.3h). The chiral complex 25b was even better than 25a, affording the same secondary alcohol in 60% ee. Two years after the initial disclosure, Hirao et al. uncovered a new catalyst system that improved the previous experimental conditions dramatically10 (Scheme 4.3i). When the chiral aminoalcohol 27, prepared from (S)-valine methyl ester hydrochloride and phenylmagnesium bromide, was used along with 2 equivalents of BH3 THF, the enantioselectivity of the alcohol 26 jumped to 94% ee. In addition, the reaction time was shortened to 2 hours. 

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