Reference

Methods for improving the efficiency of phenobarbital production

Methods for improving the efficiency of phenobarbital production. Study of the effect of individual factors on the quality of the technical-grade ester and its yield. Trifonova, L. F.; Efron, V. M.; Luttseva, A. I.; Kuznetsova, R. M. (Mosk. Khim.-Farm. Zavod im. Semashko, Moscow, USSR). Khim.-Farm. Zh., 10(10), 122-4 (Russian) 1976. CODEN: KHFZAN. DOCUMENT TYPE: Journal CA Section: 63 (Pharmaceuticals) Gas liq. chromatog. of Et ethylphenylcyanoacetate (I) [718-71-8], an intermediate product of phenobarbital [50-06-6] synthesis, revealed the presence of significant amts. of ethylphenylacetonitrile [769-68-6], which resulted in the formation of diatol (diEt carbonate) during subsequent stages of synthesis. Treatment of I with 3.5% KCl soln. at pH 3-4 prevented the formation of impurities, increased the yield of I, and economically improved the process of phenobarbital synthesis.

2-(Dialkylamino)pyridinium salts as catalysts in two-phase alkylation reactions

2-(Dialkylamino)pyridinium salts as catalysts in two-phase alkylation reactions. Tanaka, Toshio; Mukaiyama, Teruaki (Fac. Sci., Univ. Tokyo, Tokyo, Japan). Chem. Lett., (11), 1259-62 (English) 1976.Some commonly used reagents like 62166-27-2 and 769-68-6 are used in this experiment. CODEN: CMLTAG. DOCUMENT TYPE: Journal CA Section: 25 (Noncondensed Aromatic Compounds) Section cross-reference(s): 67, 24 2-(Dialkylamino)pyridinium salts, e.g., I, catalyzed the two-phase alkylation of active methylene compds. PhCH2CN, PhCHEtCN, PhCHMeCOPh, and II. The catalysts were prepd. from 2-halopyridinium salts, e.g., I was prepd. from 2-chloro-1,3-dimethylpyridinium Me sulfate by treatment first with hexadecylamine in CH2Cl2 contg. Et3N and then with Et3O+BF4-. In an example, a mixt. of PhCH2CN, EtBr, and I was stirred with 50% aq. NaOH at room temp. for 24 h to give a product contg. 90% PhCHEtCN and 3% PhCEt2CN. .