Alanine acetamide

DNA sequencing and. 1113 Electrospray ionization (ESI) mass spectrometry, 417-418 Electrostatic potential map, 37 acetaldehyde, 688 acetamide, 791,922 acetate ion. 43. 53, 56, 757 acetic acid. 53. 55 acetic acid dimer, 755 acetic anhydride, 791 acetone, 55, 56. 78 acetone anion, 56 acetyl azide, 830 acetyl chloride, 791 acetylene. 262 acetylide anion, 271 acid anhydride, 791 acid chloride, 791 acyl cation, 558 adenine, 1104 alanine, 1017 alanine zwitterion, 1017 alcohol. 75 alkene, 74, 147 alkyl halide, 75 alkyne. 74... 

The t7 -correlation for carbonylic compounds suggested by Hart et al. (1967) can be applied to additional compounds thus, 2-pyrrolidone ( =l-3xl07 m—1 sec-1) (Szutka et al., 1965), asparagine in alkaline solution ( = 2-4x 107), acetylglycine and acetyl-alanine at pH = 9 (k 107 M-1 sec-1) (Braams, 1966) react at a rate practically equal to that of acetamide (k = 1-7 x 107 m-1 sec-1) (Hart et al., 1967). The ring closure seems to have little effect on the reactivity of the carbonylic group. 

Silica-supported Lewis acids are useful catalysts with microwave irradiation for conjugate additions. The silica-supported catalysts are obtained by treatment of silica with ZnCh [Si(Zn)], Et2AlCl [Si(Al)] or TiCl4 [Si(Ti)] [ 150-152], The Michael addition of methyl a-acetamidoacrylate (196) with indole (2) under Si(M) heterogeneous catalysis assisted by microwave irradiation afforded the alanine derivative 197 within 15 min and/or bis-indolyl 198, depending on the reaction conditions (Scheme 45) [153]. While the bis-indolyl product 198 is only formed when Si(Zn) was used as catalyst, the alanine derivative 197, as a single product is formed under thermal heating in a yield of 12%. The best yields were observed with Si(Al) (Table 5). The product 198 was obtained by elimination of acetamide followed by a-Michael addition between intermediate 199 with a second mole of indole. 

Figure 9 Rank estimates for LLS fits for alanine dipeptide, neopentane, phenol, and acetamide as a function of the size of the sampling envelope. Data from CHELP LLS fits at the HF/3-21G( ) level using a sample of 1000 points.

The colorimetric responses to equivalent amounts of nitrogen as ammonia, nitrite ion, nitrate ion, and hydroxylamine are identical within experimental error. Diethylamine, ethylamine, alanine, and acetamide, each present at a concentration of 0.50 p.p.m. nitrogen, yield null response. Phosphate at a concentration of 0.50 p.p.m. phosphorus does not interfere in the determination of 1.0-p.p.m. nitrogen. There is no interference by Cu Zn-, Cd Ni-% Fe-, Pb, or Ca- each at a concentration of 10 p.p.m, in the determination of 1.0 p.p.m. nitrogen. 

Phosphonic acid amide esters. A soln. of ethyl [l-[[(phenylmethoxy)carbonyl]amino]-2-methylpropyl]phosphinate in acetonitrile under argon treated with bis(trimethyl-silyl)acetamide, followed after 1 min by L-alanine hydrochloride methyl ester, CCI4, and Et3N, the soln. stirred at room temp, for 30 min, cooled to 0°, and quenched with methanol N-[ethoxy[ 1 -[[(phenylmethoxy)carbonyl]am no]-2-methylpropyl]-... 

The above examples of Ala H peptides demonstrate that dynamical spectra are capable of capturing the dynamical behavior of the N-H" - 0=C H-bonds and their vibrational anharmonicities with remarkable accuracy, thus providing definitive assignments of the protonated alanine peptide structures produced in the gas phase. We now turn to the vibrational spectroscopy of even more challenging molecular systems, ionic clusters, displaying large vibrational anharmonicities. Details of our combined IR-PD experimental and theoretical dynamical investigations can be fotmd in [37, 65], where the structures of CP-(Methanol)i 2 and C1 NMA(H20) =o-2 clusters (NMA = A-methy 1-acetamide) have been unraveled... 

C—0 distances in crystals of urea and acetamide are 1.24 and 1.28 A. Similar distances were also found in the structures of glycine and Du-alanine to be described below. The shortening of the distances CHa—N... 

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