Abstract:
A method for the preparation of omega lactams is disclosed, more particularly epsilon caprolactam or a precursor thereof (such as cyclohexanone oxime), using as the starting material a cyclomethylene ketene, with the simultaneous formation of side products such as cyclohexanecarboxylic acid, wherein an adduct is preliminarly formed between cyclomethylene ketene and sulphur dioxide. The adduct is then reacted with a nitrosating agent so as to obtain, under the appropriate reaction conditions, the expected lactam, more specifically epsilon caprolactam.
Abstract:
THERE IS DESCRIBED A PROCESS FOR THE PREPARATION OF OMEGA-LACTAMS HAVING THE GENERAL FORMULA:
O=C WHEREIN N= FROM 2 TO 13, AND/OR OF THEIR LACTAMIZABLE PRECURSORS, WHICH MAY BE CYCLOALIPHATIC OXIMES OR CYCLOALIPHATIC NITROSO DERIVATIVES, MONOMERS OR DIMERS CHARACTERIZED BY THE FACT THAT THE CORRESPONDING CYCLOMETHYLENE KETENE, HAVING THE GENERAL FORMULA
O=C=C WHERE N HAS THE AFOREMENTIONED VALUE, IS SUBJECTED TO NITROSATION WITH A NITROSATING AGENT OF THE FORMULLA NOX, WHERE X CAN BE -HSOBJ4, -CL, -NO2, -OR (IN WHICH R INDICATES AN ALKYL OR ARYL ORGANIC SUBSTITUENT), AT A TEMPERATURE COMPRISED BETWEEN -60*C. AND + 100*C.
Abstract:
1430949 Lactams SNIA VISCOSA SOC NAZIONALE INDUSTRIA APPLICAZIONI VISCOSA SpA 27 June 1973 [28 June 1972] 30468/73 Heading C2C A lactam, e.g. caprolactam, is removed from solution in an organic first solvent by adding to the solution a second solvent which is miscible with the first solvent but which is not a solvent for the lactam so that the lactam is displaced from solution in the first solvent. Exemplified as the first solvent is a phenol containing at least one alkyl substituent which contains 3 or more carbon atoms and has a solubility in water of less than 0À5 g. per 100 g. of water at 25‹ C. and in sulphuric acid solution containing 50 g. of sulphuric acid per 50 g. of water has a solubility of less than 0À2 g. per 100 g. of acid solution at 25‹ C, the substituent groups of the phenol not hindering the activity of the OH group of the phenol. The second solvent may be an aliphatic, aromatic or chlorinated hydrocarbon. A third solvent, e.g. water which is immiscible with both the first and second solvents but which is a solvent for the lactam may also be added to the solution so that the displaced lactam forms a solution in the third solvent.
Abstract:
A method for the preparation of omega lactams is disclosed, more particularly epsilon caprolactam or a precursor thereof (such as cyclohexanone oxime), using as the starting material a cyclomethylene ketene, with the simultaneous formation of side products such as cyclohexanecarboxylic acid, wherein an adduct is preliminarly formed between cyclomethylene ketene and sulphur dioxide. The adduct is then reacted with a nitrosating agent so as to obtain, under the appropriate reaction conditions, the expected lactam, more specifically epsilon caprolactam.
Abstract:
1430949 Lactams SNIA VISCOSA SOC NAZIONALE INDUSTRIA APPLICAZIONI VISCOSA SpA 27 June 1973 [28 June 1972] 30468/73 Heading C2C A lactam, e.g. caprolactam, is removed from solution in an organic first solvent by adding to the solution a second solvent which is miscible with the first solvent but which is not a solvent for the lactam so that the lactam is displaced from solution in the first solvent. Exemplified as the first solvent is a phenol containing at least one alkyl substituent which contains 3 or more carbon atoms and has a solubility in water of less than 0À5 g. per 100 g. of water at 25‹ C. and in sulphuric acid solution containing 50 g. of sulphuric acid per 50 g. of water has a solubility of less than 0À2 g. per 100 g. of acid solution at 25‹ C, the substituent groups of the phenol not hindering the activity of the OH group of the phenol. The second solvent may be an aliphatic, aromatic or chlorinated hydrocarbon. A third solvent, e.g. water which is immiscible with both the first and second solvents but which is a solvent for the lactam may also be added to the solution so that the displaced lactam forms a solution in the third solvent.
Abstract:
A method for the preparation of omega lactams is disclosed, more particularly epsilon caprolactam or a precursor thereof (such as cyclohexanone oxime), using as the starting material a cyclomethylene ketene, with the simultaneous formation of side products such as cyclohexanecarboxylic acid, wherein an adduct is preliminarly formed between cyclomethylene ketene and sulphur dioxide. The adduct is then reacted with a nitrosating agent so as to obtain, under the appropriate reaction conditions, the expected lactam, more specifically epsilon caprolactam.
Abstract:
A method is disclosed for recovering lactams from acidic reaction mixtures, the improvement consisting in the fact that the extractant is an alkylsubstituted phenol the alkyl chain of which contains at least three carbon atoms, the alkyl substituent being capable of imparting to the phenol a lipophilic character. Monosubstituted and disubstituted phenols, such as isopropyl phenols, sec. and tert. butyl phenols, sec. and tert. amylphenols, di-sec. amylphenols and di-tert. amylphenols are preferred.