Lactic acid, 3-chloro ethyl ester

Medium Boiling Esters. Esterificatioa of ethyl and propyl alcohols, ethylene glycol, and glycerol with various acids, eg, chloro- or bromoacetic, or pymvic, by the use of a third component such as bensene, toluene, hexane, cyclohexane, or carbon tetrachloride to remove the water produced is quite common. Bensene has been used as a co-solvent ia the preparatioa of methyl pymvate from pymvic acid (101). The preparatioa of ethyl lactate is described as an example of the general procedure (102). A mixture of 1 mol 80% lactic acid and 2.3 mol 95% ethyl alcohol is added to a volume of benzene equal to half that of the alcohol (ca 43 mL), and the resulting mixture is refluxed for several hours. When distilled, the overhead condensate separates iato layers. The lower layer is extracted to recover the benzene and alcohol, and the water is discarded. The upper layer is returned to the column for reflux. After all the water is removed from the reaction mixture, the excess of alcohol and benzene is removed by distillation, and the ester is fractionated to isolate the pure ester. 

Examples 1 to 5 in Table 1.1 illustrate simple displacement of a bromide (reactions 1 and 4) or a chloride (reactions 2,3, and 5). Reaction 1 illustrates a radical chain extension reaction that reacts ethylene and methyl bromoacetate 1.17), with AIBN (flzofeis-isobutyronitrile) as a catalyst, to produce the requisite bromo-cster. The reaction is not very selective, however, since it produced a mixture of 1.18 and 1.19. The reaction was not very selective and the observed products arose from addition of one and two equivalents of ethylene, respectively, to 1.17. Subsequent treatment with ammonia, the key reaction for this section, led to a mixture of 4-aminobutanoic acid and 6-aminohexanoic acid, 1.2 and 1.4. In reaction 2, ethyl 4,4,4-trifluoropropanoate (J.20) reacted with PCI3 and bromine to give ethyl 3-bromo-4,4,4-trifluorobutanoate, which reacted with ammonia to give 3-amino-4,4,4-trifluorobutanamide, 1.21. Reaction 3 shows the reaction of P-halo lactic acid (3-chloro-2-hydroxypropanoic acid, 1.22) with 28% aqueous ammonia, in an autoclave, to give isoserine (3-amino-2-hydroxypropanoic acid, 1.23). Both halo-acids l and halo-esters 2 have been converted into hydroxy amino acids typical products are 3-... 

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See also in sourсe #XX -- [ ]

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