With Ammonia and Amines

Direct addition of ammonia to olefmic bonds would be an attractive method for amine synthesis, if it could be carried out smoothly. Like water, ammonia reacts with butadiene only under particular reaction conditions. Almost no reaction takes place with pure ammonia in organic solvents. The presence of water accelerates the reaction considerably. The reaction of aqueous ammonia (28%) with butadiene in MeCN in the presence orPd(OAc)i and PhjP at 80 C for 10 h gives tri-2,7-octadienylamine (47) as the main product, accompanied by a small amount of di-2,7-octadienylamine (46)[46,47], Isomeric branched 

The reaction of isoprcnc with Et NH in the presence of triethylammonium iodide (10 mol%) gives the 1 1 adducts 51 and 52 with high selectivity(53]. The reaction of isoprene with ammonia or diethylamine affords the tail-to-tail dimer 53 when Pdfacac) and (BuO)jP are used as the catalyst. The head-to-head dimer 54 is obtained with Pd(acac)2, BF,. and tricyclohexylphosphine(54]. 

The reaction of butadiene with the phenyihydrazone of acetone using Pd(Ph3P)4 affords the C-octadienylated products 55 and 56 and A -octadieny-lated product 57[55]. A -Methylhydrazones are jV-octadienyiated selectively [56]. 

---

Reaction with ammonia and amines (Sec tion 20 14) Acyl chlorides react with am monia and amines to form amides A base such as sodium hydroxide is normally added to react with the hydrogen chio ride produced... 

Reaction with ammonia and amines (Section 20 14) Acid an hydrides react with ammonia and amines to form amides Two molar equivalents of amine are required In the example shown only one acyl group of acetic anhydride becomes incor porated into the amide the other becomes the acyl group of the amine salt of acetic acid... 

Reactions with Ammonia and Amines. Acetaldehyde readily adds ammonia to form acetaldehyde—ammonia. Diethyl amine [109-87-7] is obtained when acetaldehyde is added to a saturated aqueous or alcohoHc solution of ammonia and the mixture is heated to 50—75°C in the presence of a nickel catalyst and hydrogen at 1.2 MPa (12 atm). Pyridine [110-86-1] and pyridine derivatives are made from paraldehyde and aqueous ammonia in the presence of a catalyst at elevated temperatures (62) acetaldehyde may also be used but the yields of pyridine are generally lower than when paraldehyde is the starting material. The vapor-phase reaction of formaldehyde, acetaldehyde, and ammonia at 360°C over oxide catalyst was studied a 49% yield of pyridine and picolines was obtained using an activated siHca—alumina catalyst (63). Brown polymers result when acetaldehyde reacts with ammonia or amines at a pH of 6—7 and temperature of 3—25°C (64). Primary amines and acetaldehyde condense to give Schiff bases CH2CH=NR. The Schiff base reverts to the starting materials in the presence of acids. 

With Ammonia and Amines. Ethylene oxide reacts with ammonia to form a mixture of mono-, di-, and triethanolamines. Nitrogen is a stronger nucleophile than oxygen (59). A small amount of water is essential for the reaction (60). 

Reaction with ammonia and amines (Section 20.14) Acid anhydrides react with ammonia and amines to form amides. 

In the second major method of peptide synthesis the carboxyl group is activated by converting it to an active ester, usually a p-nitrophenyl ester. Recall from Section 20.12 that esters react with ammonia and amines to give fflnides. p-Nitrophenyl esters are much more reactive than methyl and ethyl esters in these reactions because p-nitrophenoxide is a better (less basic) leaving group than methoxide and ethoxide. Simply allowing the active ester and a C-protected amino acid to stand in a suitable solvent is sufficient to bring about peptide bond formation by nucleophilic acyl substitution. 

Conversion of Acid Halides into Amides Aminolysis Acid chlorides react rapidly with ammonia and amines to give amides. As with the acid chloride plus alcohol method for preparing esters, this reaction of acid chlorides with amines is the most commonly used laboratory method for preparing amides. Both monosubstituted and disubstituted amines can be used, but not trisubstituted amines (R3N). 

Conversion of Esters into Amides Aminolysis Esters react with ammonia and amines to yield amides. The reaction is not often used, however, because it s usually easier to start with an acid chloride (Section 21.4). 

Picric acid, in common with several other polynitrophenols, is an explosive material in its own right and is usually stored as a water-wet paste. Several dust explosions of dry material have been reported [1]. It forms salts with many metals, some of which (lead, mercury, copper or zinc) are rather sensitive to heat, friction or impact. The salts with ammonia and amines, and the molecular complexes with aromatic hydrocarbons, etc. are, in general, not so sensitive [2], Contact of picric acid with concrete floors may form the friction-sensitive calcium salt [3], Contact of molten picric acid with metallic zinc or lead forms the metal picrates which can detonate the acid. Picrates of lead, iron, zinc, nickel, copper, etc. should be considered dangerously sensitive. Dry picric acid has little effect on these metals at ambient temperature. Picric acid of sufficient purity is of the same order of stability as TNT, and is not considered unduly hazardous in regard to sensitivity [4], Details of handling and disposal procedures have been collected and summarised [5],... 

Reaction of the Lactone Group with Ammonia and Amines... 

The esters of carbamic acid, the urethanes, which are formed by combination of alcohols with compounds of the cyanic acid series, are stable substances. The reaction by which they are formed is, likewise, capable of undergoing many variations. It may be recalled that a second method of synthesising them consists in acting on the esters of chloroformic acid with ammonia and amines. 

Fig. 2.1-16. Some typical reactions of B4IT0 with ammonia and amines.

Consequently, by choosing proper conditions, especially the ratios of the carbonyl compound to the amino compound, very good yields of the desired amines can be obtained [322, 953]. In catalytic hydrogenations alkylation of amines was also achieved by alcohols under the conditions when they may be dehydrogenated to the carbonyl compounds [803]. The reaction of aldehydes and ketones with ammonia and amines in the presence of hydrogen is carried out on catalysts platinum oxide [957], nickel [803, 958] or Raney nickel [956, 959,960]. Yields range from low (23-35%) to very high (93%). An alternative route is the use of complex borohydrides sodium borohydride [954], lithium cyanoborohydride [955] and sodium cyanoborohydride [103] in aqueous-alcoholic solutions of pH 5-8. 

In contrast to laboratory scale operations, four-bond formation processes are of considerable importance as industrial routes to pyridine derivatives and have been investigated in Considerable detail. Vapour phase condensation of aldehydes and ketones with ammonia and amines in the presence of a variety of silica/alumina catalysts containing different promoters (e.g. cobalt(II) chloride) can give excellent yields of substituted pyridines (e.g. equation 151), and the nature of the products formed can be largely controlled by change in the stoichiometry of the reactants and variation of experimental conditions (equation 152). 

D. M. Roundhill, Chem. Rev. 92, 1-27 (1992) . .Transition Metal and Enzyme Catalyzed Reactions involving Reactions with Ammonia and Amines". 

NH20S03H reacts with ammonia and amines to give, respectively, hydrazine and substd hydrazines... 

---