Process, continuous amines from alcohols

Batch or continuous processes can be used to prepare tertiary amines from alcohols and ammonia or a secondary amine, such as, dimethylamine. 

Primary amines can be prepared from alcohols and an excess of ammonia (52—55). Either a batch or continuous process can be used. The reaction is mn at elevated temperature (50—340°C) and high pressure, 3.5 MPa (500 psig), with an ammonia-to-alcohol ratio of 5 1 to 30 1. 

A variety of ion exchange resins with strong and weak acid, weak base, and quaternary ammonium ion functionality are available in bead form well suited for filtration from reaction mixtures and for use in continuous flow processes. They have been used for >30 years in flow systems for water deionization. Sulfonic acid resins are already used on a large scale as catalysts for the addition of methanol to isobutylene to form methyl terr-butyl ether, for the hydration of propene to isopropyl alcohol, and for a variety of smaller scale processes. Tertiary amine resins have been used as catalysts for the addition of alcohols to isocyanates to form urethanes. The quaternary ammonium ion resins could be used as reagents with any of a large number of counter ions, and as catalysts in two and three phase reaction mixtures, although the author is not aware of any commercial process of this sort at present. 

Oxazolidine-2,5-diones (276) are the anhydrides of iV-carboxy-a-amino acids. They react with nucleophiles, such as water, alcohols or amines, to give unstable N-carboxy acids, esters or amides which lose carbon dioxide (equation 87). The products (277) are themselves nucleophilic reagents and may react with another molecule of the oxazolidinedione to yield a dipeptide (equation 88). The process may continue, leading to a polypeptide. Chiral oxazolidine-2,5-diones derived from optically active a-amino acids undergo stereospecific polymerization (72C501). 

---