Dane salt

Methyl acetoacetate (MAA) and ethyl acetoacetate (EAA) are the most widely used esters they are found ia the pharmaceutical, agricultural, and allied industries. Both esters are used extensively as amine protecting agents ia the manufacture of antibiotics and synthetic sweeteners (Dane Salts) (147). Principal outiets for MAA are the manufacture of the organophosphoms insecticide dia2inon [33341-5] (148,149) and the uracil herbicides bromacil [31440-9] and terbacil [5902-51-2] (150,151) (see Insect conztiol technology Herbicides). 

It is quickly deacylated in vivo and may qualify as a prodrug. The published synthesis is rather long and bears conceptual similarities to the synthesis of cannabinoids. It has some five asymmetric centers. Dane salt formation between 3,5-di-methoxyani1ine and ethyl acetoacetate followed by borohydride reduction gives synthon The amino group is protected by... 

A different approach has been used for the synthesis of amoxicillin (Figure 6.18). Based on the application of the inexpensive Dane salt of 4-hydroxyphenylglydne, a process has been developed giving the required compound in almost quantitative yield. 

Figure 6.18 Chemical synthesis of amoxicillin from 6-aminopenicillanic acid via the Dane Salt of 4-hydroxyphenylglycine.

A practical synthesis of a-amido 3-lactams uses a Dane salt (9) formed by the reaction of a methan-olic solution of the potassium salt of glycine with methyl acetoacetate (Scheme 9). The salt (9) readily reacts with a Schiff base in the presence of triethylamine and e.g. a chloroformate ester. Other activating agents such as phenyl dichlorophosphate - or phosphorus oxychloride - have also been successfully used. 

D-( —)-a-Dihydrophenylglycine chloride hydrochloride D-(—)-a-Dihydrophenylglycine Dane salt methyl sodium D-(3.4-Dihydroxy)-a-phenylglycine... 

D-(—)-a-/>-Hydroxyphenylglycine Dane salt ethyl potassium C14H14NO5K... 

D-(—)-a-7 -Hydroxyphenylglycine Dane salt methyl sodium CisHnNOsNa... 

D-(—)-a-Phenylglyeine Dane salt (potassium, ethyl) D-( —)-a-Phenylglyeine methyl ester HCl (A)-(—)-a-Pheny Igly einol... 

Amino-substituted )S-lactams are accessible by reaction of furfiirylimine 767 with the Dane salt 770 in the presence of phenyl dichlorophosphate. The resulting cis-p-lactam 771 is formed with a diastereomeric excess of 91%. Compound 772 is converted to methyl ketone... 

Dane salt, 178 dapsone, 151 daunomydn, 182 de-esterincations, 185 deaminations, 185 decoloiisation, 249,251 degree of reductance, 41 dehydrations, 185 dehydrogenases, 13 dehydrogenations, 320 delta lactones, 145 demethylations, 185... 

Uses Copromoter for cobalt-contg. polyester-accelerator systems solvent for cellulose ethers extractant ingred. of solvent mixts. for cellulose esters synthesis of nifedipine (a cardiac drug) org. synthesis reagent for Dane salt formation intermediate for vitamins, feed additives, pharmaceuticals, pesticides component for flavors and fragrances solvent for fragrances in cosmetics prod, of azo dyes Manuf./Distrib. Aceto http //www.aceto.com,... 

A safe synthesis of 2-vinylamino-/3-lactams by the reaction of a Schiff base from veratrylamine and cinnamaldehyde with a-methyl-jS-alkoxycarbonylvinyl-aminoacetic acid ( Dane Salt ), as shown in Scheme 125, has been described. 

Yields are good and the compounds can be converted by literature methods into known intermediates useful in the synthesis of iso-cephalosporins and related compounds. A similar approach has been reported in which glycine is used as a component of the Dane Salt and the Schiff base (Scheme 126). ... 

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