Formamidine sulfonic acid

Continuous polymerization is a second process practiced on a large commercial scale (88). An illustrative example taken from the patent literature illustrates the continuous polymerization process. Thus a mixture of chloroprene, 2,3-dichloro-l,3-butadiene, dodecyl mercaptan, and phenothiazine (15 ppm) was fed to the first of a cascade of seven reactors. Water solution containing dispropor-tionated potassium abietate, potassium hydroxide, and formamidine sulfonic acid catalyst were fed with the monomer solution to the first reactor. Polymerization initiated immediately. The emulsion was then cascaded to the second reactor and the process continued. The residence time in each reactor was 25 min at 45°C. The emulsion exited the reaction train at 66% monomer conversion. In a second similar process, the catalyst was fed to each reactor along the reaction train. 

The guanidine derivative 48 has been prepared by treating l,5-dideoxy-l,5-imino-xylitol (see Vol. 24, p. 197, ref. 33 for its preparation) with formamidine-sulfonic acid. 

Heterocycles Acetylacetone. N-Aminophthalimide. Boron trichloride. Dichloro-formoxime. Oicyanodiamide. Dicyclohexylcarbodiimide. Dietboxymethyl acetate. Diethyl oxalate. Diketene. Dimethylformaniide diethylacetal. Diphenyldiazomethene. Ethyl ethoxy-methylenecyanoacetate. Formaldehyde. Formamide. Formamidine acetate. Formic acid. Glyoxal. Hydrazine. Hydrazoic acid. Hydroxylamine. Hydroxylamine-O-sulfonic acid. Methyl vinyl ketone. o-Phenylenediamine. Phenylhydrazine. Phosphorus pentasullide. Piperidine. Folyphosphoric acid. Potassium diazomethanedisulfonate. Sodium ethoxide. Sodium nitrite. Sodium thiocyanate. Tetracyanoethylene. Thiosemicarbozide. Thiourea. Triethyl orthoformate. Tris-formaminomethane. Trityl perchlorate. Urea. Vinyl triphenyl-phosphonium bromide. 

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