Lactam sulfate

In the continuous process the oxime solution (which is acidified with sulfuric acid) is passed through the reaction zone that is kept at the rearrangement temperature of 90 to 120°C. The rearrangement is complete within a few minutes, and the resulting lactam sulfate solution is converted into... 

Ingredients. Nylon-6 is produced commercially from caprolactam [105-60-2] which is the most important lactam industrially. AH industrial production processes for caprolactam are multistep and produce ammonium sulfate [7783-20-2] or other by-products. Approximately 95% of the world s caprolactam is produced from cyclohexanone oxime [100-64-1] via the Beckmann rearrangement (144). The starting material for cyclohexanone can be... 

An additional mole of ammonium sulfate per mole of final lactam is generated duting the manufacture of hydroxylamine sulfate [10039-54-0] via the Raschig process, which converts ammonia, air, water, carbon dioxide, and sulfur dioxide to the hydroxylamine salt. Thus, a minimum of two moles of ammonium sulfate is produced per mole of lactam, but commercial processes can approach twice that amount. The DSM/Stamicarbon HPO process, which uses hydroxylamine phosphate [19098-16-9] ia a recycled phosphate buffer, can reduce the amount to less than two moles per mole of lactam. Ammonium sulfate is sold as a fertilizer. However, because H2SO4 is released and acidifies the soil as the salt decomposes, it is alow grade fertilizer, and contributes only marginally to the economics of the process (145,146) (see Caprolactam). 

Properties. Thienamycin is isolated as a colorless, hygroscopic, zwitterionic soHd, although the majority of carbapenems have been obtained as sodium salts and, in the case of the sulfated olivanic acids, as disodium salts (12). Concentrated aqueous solutions of the carbapenems are generally unstable, particularly at low pH. AH the substituted natural products have characteristic uv absorption properties that are often used in assay procedures. The ir frequency of the P-lactam carbonyl is in the range 1760 1790 cm . ... 

Fuming sulfuric acid containing 10-60% sulfur trioxide hydrolyzes perfluoro-Af-alkylcyelic amines to perfluoro-Al-alkyl lactams. Mercuric sulfate acts as a Catalyst [JO, 31] (equation 33). The lactams ate highly reactive and can be used to prepare polymenc films and surfactants... 

A further modification is a single (3-lactam ring as found in the mon-obactams. Characteristically, there is a sulfonate residue (derived from sulfate) on the nitrogen atom. An example is sulfazecin 8 from Pseudomonas acidophila and P. mesoacidophila. This material also contains a dipeptide unit of D-glutamate and D-alanine (Scheme 2). Pharmaceutical chemists have synthesized many variations on the (3-lactam structure and have devised semisynthetic processes. The resulting materials are not natural products and are beyond the scope of this article. 

Solutions of cefepime, like those of most -lactam antibiotics, should not be added to solutions of ampicillin at a concentration greater than 40 mg/mL, and should not be added to metronidazole, vancomycin, gentamicin, tobramycin, netilmicin sulfate, or aminophylline because of potential interaction. However, if concurrent therapy with cefepime is indicated, each of these antibiotics can be administered separately. P.877... 

The preparation of fulvene enamines by the reaction of sodium cyclopent-adienide with dimethyl sulfate complexes of amides or lactams has recently been reported by several investigators [77, 78] (Eq. 22). 

Resin bound amines 26 were condensed with ort/io-nitrobenzaldehyde in dichloromethane in the presence of anhydrous sodium sulfate as drying agent to furnish the imines 27. Cycloaddition [2 + 2] of 27 with ketene was carried out in dichloromethane at —78°C. The ketene was generated in situ from corresponding phenoxyacetyl chloride in the presence of triethylamine. In all cases, c/s-p-lactams... 

A large number of compounds used as catalysts in acid-ion lactam polymerization are known. These include alkalis, alkali-earth metals, hydrates, Grignard reagents, lithium oxide, various hydroxides and carbonates, sulfates, halides, sodium zincate, alkaline salts of different acids, i.e., compounds that cause the formation of lactam acid ion in the reactive medium. The mechanism of polymerization in the presence of sodium-lactam- salt compounds is largely known. 

Scheme 2 shows Rapoport s synthesis [15]. The cinnamic acid derivative 3 prepared from m-methoxy benzaldehyde [20] was ethylated by diethyl sulfate to give ethyl cinnamate derivative 4, followed by Michael addition with ethyl cyanoacetate to afford compound 5. Compound 5 was converted to lactam 6 by the reduction of the cyano group and subsequent cyclization. Selective reduction of the lactam moiety of 6 was achieved by treatment with trimethy-loxonium fluorob orate followed by sodium borohydride reduction. Amine 8 was obtained by the reductive methylation of amine 7. Amine 8 was converted to compound 9 by methylene lactam rearrangement [21], followed by selenium dioxide oxidation to provide compound 10. Allylic rearrangement of compound 10 and subsequent hydrolysis gave compound 12. The construction of the decahydroisoquinoline structure began with compound 12,... 

Lactams and some non-cyclic, secondary amides (RCONHR) can be alkylated with high regioselectivity either at nitrogen (Section 6.6) or at oxygen. N-Alkylations are generally conducted under basic reaction conditions whereas O-alkylations are often performed with trialkyloxonium salts, dialkyl sulfates, or alkyl halides/silver salts without addition of bases. Protonated imino ethers are formed these are usually not isolated but are converted into the free imino ethers with aqueous base during the work-up. Scheme 1.8 shows examples of the selective alkylation of lactams and of the formation of 2-pyrrolidinones or 2-iminotetrahydrofurans by cycli-zation of 4-bromobutyramides. 

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