CAS No 165450-17-9 , (3S)-3-(3,
3-dimethylbutylamino)-4-[[(2S)-1-methoxy-1-oxo-3-phenylpropan-2-yl]
amino]-4-oxobutanoic acid

Title: Neotame
CAS Registry Number: 165450-17-9
CAS Name: N-(3,3-Dimethylbutyl)-L-a-aspartyl-L-phenylalanine 2-methyl ester
Synonyms: N-[N-(3,3-Dimethylbutyl)-L-a-aspartyl]-L-phenylalanine 1-methyl ester
Molecular Formula: C20H30N2O5
Molecular Weight: 378.46
Percent Composition: C 63.47%, H 7.99%, N 7.40%, O 21.14%
Literature References: Alkylated dipeptide reported to be 6000 to 10000 times sweeter than sucrose; structurally related to aspartame, q.v. Prepn: C. Nofre, J.-M. Tinti, FR 2697844; eidem, US 5480668 (1994, 1996); and sweetness evaluation: I. Prakash et al., Synth. Commun. 29, 4461 (1999). Crystal structure: D. J. Wink et al., Acta Crystallogr. C55, 1365 (1999). Analysis of polymorphic forms: B. E. Padden et al., Anal. Chem. 71, 3325 (1999). Review of discovery, properties, and utility: C. Nofre, J.-M. Tinti, Food Chem. 69, 245-257 (2000).
Properties: Occurs as the monohydrate. White crystalline powder from ethyl acetate/hexane, mp 80-83°; also reported as mp 80.9-83.4° from aq MeOH. [a]D -54.84° (c = 1 in methanol); [a]D20 -39.8° (c = 0.5 in water). pKa1 3.01; pKa2 8.02. pI: 5.5. Caloric value: <1.2 kJ/g. Soly in water (g/l): 10.6 (15°), 12.6 (25°), 47.5 (60°); in ethyl acetate (g/l): 43.6 (15°), 77 (25°), >1000 (60°); in abs ethanol (g/l): ~950 (25°).
Melting point: mp 80-83°; mp 80.9-83.4° from aq MeOH
pKa: pKa1 3.01; pKa2 8.02
Optical Rotation: [a]D -54.84° (c = 1 in methanol); [a]D20 -39.8° (c = 0.5 in water)
Use: Non-nutritive sweetener.