Ammonia → Caprolactam

HRID 2271228Notes

Reaction equation

HRID 2271228 reaction equation
[CH:1]([CH2:3][CH2:4][CH2:5][CH2:6][C:7]([O:9][CH3:10])=[O:8])=[O:2].[NH3:11].[H][H]>CO>[NH2:11][CH2:1][CH2:3][CH2:4][CH2:5][CH2:6][C:7]([O:9][CH3:10])=[O:8].[C:1]1(=[O:2])[NH:11][CH2:7][CH2:6][CH2:5][CH2:4][CH2:3]1

Participants

6

Reactant 3

HCID 222AmmoniaHCID 81164Methyl 6-oxohexanoateHCID 178418361HCID 178418361, compound

Product 2

HCID 7768CaprolactamHCID 1810164Methyl 6-aminohexanoate

Reagents, catalysts & solvents 1

HCID 887MethanolSolvent

Procedure

Such a process is described in U.S. Pat. No. 4,731,445. This publication describes a process in which first methyl 5-formylvalerate is contacted with ammonia and hydrogen in the presence of methanol as solvent and a hydrogenation catalyst. In this step methyl 6-aminocaproate and a small amount of ε-caprolactam is obtained. In a second step, the excess ammonia and hydrogen are removed from the reaction mixture. In a third step, the methyl 6-aminocaproate is reacted with water in the presence of a small amount (0.1 to 2 wt. %) of ammonia at a temperature of 50 to 250 ° C. The released methanol is simultaneously removed. Example 1 of U.S. Pat. No. 4,731,445 discloses the reaction of methyl 6-aminocaproate with water in the presence of an almost negligible amount of ammonia at a temperature of about 100° C. The resulting aqueous mixture, which mixture contains 6-aminocaproic acid and small amounts of 6-minocaproamide and ε-caprolactam, is heated to a emperature of 330° C. In this step the 6-aminocaproic acid and 6-aminocaproamide reacts by cyclization to ε-caprolactam.

Sources & evidence

ORD record
ord-0c4f98ac782a4c91b1e9575b625b646a
Source dataset
uspto-grants-2001_12
Patent number
US06333412B1

Reaction notes

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