Chloroform, hydrolysis

Isocyanide reaction. Heat together gently 0 2 g. of the anilide, 3 ml. of ethanolic NaOH solution and i ml. of chloroform hydrolysis of the anilide occurs, and the odour of the isocyanide can be detected after about i minute s heating. [This test clearly differentiates an anilide of type R CONHC Hj from one of type R CO N(CH3)CeH5.]... 

Chloroform is more rapidly hydrolyzed with base than dichloromethane or carbon tetrachloride and gives not only formic acid but also carbon monoxide Hine has shown that the mechanism of chloroform hydrolysis is quite different from that of dichloromethane or carbon tetrachloride, though superficially the three reactions appear similar. The first step is the loss of a proton to give CCla , which then loses Cl to give dichlorocarbene CCI2, which is hydrolyzed to formic acid or carbon monoxide. 

As with most of the synthetic polysaccharides, complete methylation189 of the polyxylose was difficult. The fully methylated polymer was soluble in petroleum ether (30-60°) containing 6% of chloroform. Hydrolysis of the methylated xylan gave tri-, di-, and mono-O-methyl-D-xyloses, together with D-xylose, in the molar ratio of 31 33 19 5. The tri-O-methyl-D-xylose fraction contained 38% of 2,3,5-tri-O-methyl-D-xylose, the remainder being the 2,3,4-trimethyl ether. The dimethyl ethers included the 2,5-,... 

O-Benzylation of 148 with benzyl bromide in the usual manner yielded the tri-0-benzyl derivative (149), [a]p7 —0.8° (chloroform). On hydrolysis with aqueous acetic acid, 149 gave the compound (150), which was further converted to the compound (151) by sodium borohydride reduction. Periodic acid oxidation of 151 and successive sodium borohydride reduction gave 5,6-di-<9-acetyl-2,3,4-tri-0-benzyl-pseudo-a-L-altropyranose (152), [a] 6 —25.7° (chloroform), after conventional acetylation. Reductive cleavage of 152 with sodium in liquid ammonia and subsequent acetylation afforded pseudo-a-L-altropyranose pentaacetate (153), m.p. 84-85 °C, [ ]q6 —13.7° (chloroform). Hydrolysis of 153 gave 154, [ot] —43.6° (methanol) [35] (Scheme 24). 

Very early experiments revealed that the amine was absolutely critical in the first step of the reaction, hydrolysis. In the absence of any amine catalyst, chloroformate could be recovered virtually unreacted from the interfacial mixture even when pH s approached 14. If base catalysis were the dominant means of chloroformate hydrolysis, then typical phase-transfer catalysts in the presence of sodium hydroxide should at least promote hydrolysis of chloroformate to phenols. However, a variety of phase-transfer catalysts, including n-Bu4N" OH, produced little or no reaction of the bischloroformate during the time frame of a normal cyclization reaction. Under homogeneous conditions or very long reaction times, the chloroformate can be consumed to produce primarily linears and polymer with negligible levels of cyclics. 

Micellar Effects.—Some of the most dramatic effects have been reported for bi-molecular reactions between ions of like charge, for example [Co(NH3)5Br] and fjg3+128 jjjjg reaction, and analogous reactions involving such complexes as [Co(NH3)6(N3)] + and such metal ions as Cr +, Pb +, Cd +, and V +, have been reviewed. The relative reactivity of metal ions in such micellar systems is not always easy to rationalize, as for instance of catalysis of benzyl chloroformate hydrolysis. ... 

The conditions must be strictly adhered to and low laboratory temperatures must be avoided also the reaction mixture must not be heated, otherwise the excess of alkali decomposes the chloroform formed and high results are obtained. This was confirmed by Harrington, Boyd and Cherry who showed that some hydrolysis of the chloroform occurred at room temperature in the excess of alkali present. If, after neutralisation of the excess alkali, the chloride formed is titrated with OTN silver nitrate using potassium chromate as indicator, a correction for this hydrolysis is possible. Since 3 mols. of sodium chloride produced are equivalent to 4 mols. of sodium hydroxide required for the chloroform hydrolysis, 2/15 of the silver nitrate titration must be deducted from the N sodium hydroxide absorbed in the original hydrolysis. 

Copolymerization of the multimonomers was carried out in a dilute solution in DMF at 90 °C using AIBN as an initiator. The copolymerization product was soluble in DMF and in chloroform. Hydrolysis of the copolymer obtained, followed by separation and analysis showed that one of the products of the hydrolysis is poly(vinyl alcohol) with a molecular weight similar to that of the initial PVA. 

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