Arylation ammonia

Reaction with chlorosulphonic acid ( chlorosulphonyl-ation ). Sulphonamides. Many aryl hahdes, either alone or in chloroform solution, when treated with excess of chlorosulphonic acid afford the corresponding sulphonyl chlorides in good yield (compare Section IV.106) the latter may be readily converted into the aryl sulphonamides by reaction with concentrated ammonia solution or with sohd ammonium carbonate. 

The action of ammonia on N-(5-aryl-l,3-oxathioI-2-ylidene) tertiary iminium salts (7) affords linear intermediates that cyclize to 2-amino-4-phenylthiazoles (Scheme 7) (45). 

The action of ammonia on N-(aryl-i,3-oxathiol-2-ylidine) tertiary im-inium salts (254) yields linear intermediates (255) that cyclize to 2-amino-4-phenyl thiazoles (256) on crystallization from acetic acid (Scheme 129) (730). 

Aryl halides do not normally react with ammonia under these conditions The few exceptions are special cases and will be described m Section 23 5... 

Amines are derivatives of ammonia in which one or more of the hydrogens is replaced with an alkyl, aryl, cycloalkyl, or heterocycHc group. When more than one hydrogen has been replaced, the substituents can either be the same or different. Amines are classified as primary, secondary, or tertiary depending on the number of hydrogens which have been replaced. It is important to note that the designations primary, secondary, and tertiary refer only to the number of substituents and not to the nature of the substituents as in some classes of compounds. 

V-Alkyl or A/-aryl succinimides can be prepared from the corresponding amines (107) or from succinic anhydride, ammonia, and the corresponding alcohol (108). Succinimides are also obtained by vapor-phase hydrogenation of the corresponding maleimides ia the presence of a catalyst (109). 

Another exceUent method for preparing tertiary stibines involves the interaction of an organostibide and an alkyl or aryl haHde (91,92). This method is of particular value in preparing un symmetrical tertiary stibines. For example, an interesting hybrid ligand has been obtained by the foUowing reaction carried out in Hquid ammonia (93) ... 

An aryl methanesulfonate was cleaved to a phenol by phenyllithium or phen-ylmagnesium bromide it was reduced to an aromatic hydrocarbon by sodium in liquid ammonia. ... 

A second general reaction that proceeds by an SrnI mechanistic pattern involves aryl halides. Aryl halides undergo substitution by eertain nueleophiles by a ehain mechanism of the SrnI class.Many of the reactions are initiated photochemically, and most have been conducted in liquid ammonia solution. 

Reductive amination (Section 22.10) Reaction of ammonia or an amine with an aldehyde or a ketone in the presence of a reducing agent is an effective method for the preparation of primary, secondary, or tertiary amines. The reducing agent may be either hydrogen in the presence of a metal catalyst or sodium cyanoborohy-dride. R, R, and R" may be either alkyl or aryl. 

Reactivity in this ring system is sufficient for facile hydrolysis (20°, 2 hr or 100°, 1 min) of the 2-, 4-, 6-, and 7-methoxypteridines in high yield and for easy substitution (75-90% yields) of the 7-methylthio group with methanolic hydrazine hydrate (65°, 15 min), dimethylamine (65°, 30 min), and ethanolic ammonia (125°, 6 hr). The 7-acyloxy intermediate in thionation of 7-oxopteridine with phosphorus pentasulfide is readily substituted (80°) to form pteridine-7-thione. The chloro group in 6-aryl-2,4-diamino-7-chloro-pteridine still reacts readily with hydrazine (100°, several minutes) in spite of the two deactivating amino substituents. 

Similarly, a number of l-alkyl(aryl)-4-ehloro-3-nitro-l,8-naphthyridin-2 (IH)-ones (100) have been reported to reaet with ammonia or alkylamines to afford the eorresponding 4-amino eompounds [101, R = H, CH3, C2H5, CH(CH3)2, CH2 CfiHs] (91JHC2029, 91MI2 92JMC4866). 

Heating of an aryl hydrazone 1 in the presence of a catalyst leads to elimination of ammonia and formation of an indole 2. This reaction is known as the Fischer indole synthesisy and is somewhat related to the Benzidine rearrangement. 

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