Ferric chloride, in addition of chloroform

Ferric chloride in addition of chloroform to olefins, 46,104 Fluoroacetyl fluoride, 46, 6 2-Fluoroalkanoic acids from 1-alkenes,... 

Crich and Rumthao reported a new synthesis of carbazomycin B using a benzeneselenol-catalyzed, stannane-mediated addition of an aryl radical to the functionalized iodocarbamate 835, followed by cyclization and dehydrogenative aromatization (622). The iodocarbamate 835 required for the key radical reaction was obtained from the nitrophenol 784 (609) (see Scheme 5.85). lodination of 784, followed by acetylation, afforded 3,4-dimethyl-6-iodo-2-methoxy-5-nitrophenyl acetate 834. Reduction of 834 with iron and ferric chloride in acetic acid, followed by reaction with methyl chloroformate, led to the iodocarbamate 835. Reaction of 835 and diphenyl diselenide in refluxing benzene with tributyltin hydride and azobisisobutyronitrile (AIBN) gave the adduct 836 in 40% yield, along with 8% of the recovered substrate and 12% of the deiodinated carbamate 837. Treatment of 836 with phenylselenenyl bromide in dichloromethane afforded the phenylselenenyltetrahydrocarbazole 838. Oxidative... 

Crystals from dil ale, mp 256 (dec). Sublimes. Sol in boiling water, hot dil alcohol, hot glacial acetic acid very sparingly sol in ether, in carbon bisulfide, in chloroform, in benzene. Sol in alkali and alkali carbonate solns giving a yellow color. Aq solns give a green color with ferric chloride which turns red on addition of sodium carbonate. 

MDI method For determination of 4,4 -diphenylmethane diisocyanate in the atmosphere, 5 litres of air should be drawn through 3 ml of 0-4n hydrochloric acid. After the addition of three drops of a 0-6% (w/v) sodium nitrite solution six drops of 10% (w/v) sulphamic acid should be added and the mixture transferred to a separating funnel containing 2 ml of 1 n sodium hydroxide solution and six drops of a suspension of 0-5 g of 2-hydroxy-3-naphthoic anilide (Brenthol AS) in 50 ml water. This mixture is then shaken and 1 ml of 6n sulphuric acid followed by 3 ml of chloroform are added. This is shaken and the chloroform layer separated off. The colour of this chloroform layer is then compared with standard colour solutions prepared by mixing a solution of cobaltous chloride (as above) with a solution of 32 g anhydrous ferric chloride, 25 ml concentrated hydrochloric acid (SG 20°C 1-18) and 975 ml water. The proportions of these two solutions equivalent to different levels of atmospheric diisocyanate are given in Table 11.3. 

---