Title: Girard Reagents
Literature References: Quaternary ammonium acetylhydrazine chlorides which form water-soluble hydrazones with carbonyl compounds. The hydrazones formed can subsequently be hydrolyzed in order to regenerate the original carbonyl compounds. Prepn: A. Girard, G. Sandulesco, GB 6640 (1934); eidem, Helv. Chim. Acta 19, 1095 (1936); A. Girard, Org. Synth. coll. vol. II, 85 (1943). Review: Wheeler, Chem. Rev. 62, 205 (1962). Use of Girard reagents in separation of carbonyl compounds: Schubert, Wehrberger, Endokrinologie 48, 70 (1965); R. E. J. Mitchel, H. C. Birnboim, Anal. Biochem. 81, 47 (1977); W. Holstein, D. Severin, Erdoel Kohle, Erdgas, Petrochem. 32, 487 (1979); C.A. 92, 44207b (1980).
Derivative Type: Girard reagent T
Additional Names: 2-Hydrazino-N,N,N-trimethyl-2-oxoethanaminium chloride; (carboxymethyl)trimethylammonium chloride hydrazide; betaine hydrazide hydrochloride
Molecular Formula: C5H14ClN3O
Molecular Weight: 167.64
Percent Composition: C 35.82%, H 8.42%, Cl 21.15%, N 25.07%, O 9.54%
Properties: Highly hygroscopic needles. May be stored in well-stoppered containers. Material that has developed an odor should be recrystallized from abs ethanol. mp 192° (slight decomp). Very freely sol in water; sol in about 150 parts of absolute ethanol; more sol in methanol. Also very sol in acetic acid, glycerol, ethylene glycol. Practically insol in organic solvents devoid of hydroxyl groups.
Melting point: mp 192° (slight decomp)
Derivative Type: Girard reagent P
Additional Names: 1-(2-Hydrazino-2-oxoethyl)pyridinium chloride
Molecular Formula: C7H10ClN3O
Molecular Weight: 187.63
Percent Composition: C 44.81%, H 5.37%, Cl 18.90%, N 22.40%, O 8.53%
Properties: Non-hygroscopic crystals from methanol, dec 200°. Less soluble in polar solvents than Girard reagent T.
Use: In the isoln of 17-ketosteroids and other carbonyl compounds. |