CAS No 14338-32-0 , 2-chloro-1-methylpyridin-1-ium

Title: Mukaiyama Reagent
CAS Registry Number: 14338-32-0
CAS Name: 2-Chloro-1-methylpyridinium iodide
Synonyms: 2-chloropyridine methiodide; 1-methyl-2-chloropyridinium iodide
Molecular Formula: C6H7ClIN
Molecular Weight: 255.48
Percent Composition: C 28.21%, H 2.76%, Cl 13.88%, I 49.67%, N 5.48%
Literature References: Acid-activating agent for prepn of carboxylic esters. Prepn: M. Liveris, J. Miller, Aust. J. Chem. 2, 297 (1958); and reactions with hydroxide ions: G. B. Barlin, J. A. Benbow, J. Chem. Soc. Perkin Trans. 2 1974, 790. Use in synthesis of carboxylic esters: T. Mukaiyama et al., Chem. Lett. 1975, 1045; T. Mukaiyama, Angew. Chem. Int. Ed. 18, 707 (1979). Kinetic resolution of carboxylic acids and alcohols: A. Mazón et al., Tetrahedron: Asymmetry 3, 1455 (1992). Kinetics of nucleophilic substitution reactions with primary and secondary amines: A. Awwal et al., Indian J. Chem. 40B, 32 (2001); with phenols: M. Kabir et al., ibid. 43B, 1779 (2004). Use in synthesis of ketenes: R. L. Funk et al., Synlett 1989, 36; of b-lactams: C. M. L. Delpiccolo et al., J. Comb. Chem. 5, 208 (2003); of esters: D. Donati et al., Tetrahedron Lett. 46, 2817 (2005).
Properties: Almost colorless needles, mp 207° (Liveris, Miller). Also reported as pale yellow crystals, mp 205-206° (dec) (Barlin, Benbow). uv max (pH 7.0): 213, 274 nm (log e 3.66, 3.86).
Melting point: mp 207° (Liveris, Miller); mp 205-206° (dec) (Barlin, Benbow)
Absorption maximum: uv max (pH 7.0): 213, 274 nm (log e 3.66, 3.86)
Use: Condensation reagent for the synthesis of esters and ketenes, and for the kinetic resolution of carboxylic acids and alcohols.