veoexrmpzt
Dołączył: 21 Lut 2011
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 Wysłany: Pon 13:52, 14 Mar 2011 Temat postu: herve leger sale utc euj rgbd ejy |
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7 - alkyl amino acid to the acetoxy synthesis of cephalosporin
Sulfone concentration of reference substance under different reflux time and the resultant acid reactants ring expansion of penicillin G sulfoxide acid relative content in Table 1. Table 1, the relative content of % 1.3 resultant cleaved 10g ring enlargement reaction acid suspended in 50mL water, dropping P = 5% NH,[link widoczny dla zalogowanych], H: 0, keeping pH7.5 ~ 8, the ring enlargement acid solution , add 0.5g activated carbon, at room temperature stirred 30min, filtered , washed . Filtrate was heated to 35c 【 = heat ,[link widoczny dla zalogowanych], add 10g acylase , water adjusted to 1000mL, with 5% 84NH, HO maintained PH7.5 ~ 8, reaction 120min, to essentially the same pH , filtration, washing . Adjusted with concentrated HC1 solution pH to 3.7 , stirring 1h, filtered , washed . 50 ℃ drying, 7 a ADCA5.6g,[link widoczny dla zalogowanych], yield 87.5%. Determined by HPLC ,[link widoczny dla zalogowanych], the chromatograms ( Figure 6) and reference substance in the chromatogram (Figure 7) consistent. Figure 67 A sample chromatogram of Figure 77 ADCA ADCA reference standard chromatogram of a 2 Results and discussion 2.1 ring expansion using a rearrangement of trimethylsilyl urea carboxyl protective agent to do , easy on the protection,[link widoczny dla zalogowanych], but also easy off protection. Deprotection reaction steps can be reduced . 2.2 The ring enlargement of a rearrangement reaction by RP- HPLC monitoring , when reflux 140min , the expanding ring the highest acid content , namely that the reaction end point. Extend the time as reflux , acid content and reduced expansion ring , said ring enlargement acid was partially destroyed. 2.3 acylase cleavage of ring expansion using acid side chain , mild reaction , high yield . And no waste discharge , the mother liquor can be recycled by-products - acid . 2.4 The process route to = 20% CH, CO, H as oxidant , the oxidation of penicillin G potassium salt of penicillin G sulfoxide acid; to do with three carboxyl methyl urea protective agent , pyridine hydrobromide as a catalyst for ring expansion Re- arranged in a ring enlargement acid; under the action of the enzyme in the acylation , a cracking 7 ADCA. This line of advanced technology , mild reaction , the total yield of 65.7% , higher than reported in the literature at home and abroad (up to 46%).
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