Amines, Isothiocyanates, Nitriles

1 Preparation of Propargylk Tertiary Amines from Propargyl Bromide and Aliphatic or Cycloaliphatic Secondary Amines 

Propargyl bromide reacts sluggishly with the bulky diisqpropylamine (yields are low). 

2 Propargyl Dimethvlamine from Propargyl Bromide and Dimethylamine petroleum ether 

3 Propargyiamine from Propargyl Bromide and Liquid Ammonia liq. NH3 

Apparatus 5-1 wide-necked, round-bottomed flask after the addition a rubber stopper with a narrow hole is placed on the flask the flask is insulated by cotton wool. 

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AletalHydrides. Metal hydrides can sometimes be used to prepare amines by reduction of various functional groups, but they are seldom the preferred method. Most metal hydrides do not reduce nitro compounds at all (64), although aUphatic nitro compounds can be reduced to amines with lithium aluminum hydride. When aromatic amines are reduced with this reagent, a2o compounds are produced. Nitriles, on the other hand, can be reduced to amines with lithium aluminum hydride or sodium borohydride under certain conditions. Other functional groups which can be reduced to amines using metal hydrides include amides, oximes, isocyanates, isothiocyanates, and a2ides (64). 

An unusual reaction leading to formation l-substituted-4-thioxopyrazolo[3,4-phenyl isothiocyanate in DMF saturated with hydrogen chloride gives derivatives (317) (Scheme 27). A proposed reaction sequence involves initial electrophilic addition of phenyl isothiocyanate to the protonated o-amino-nitrile to give an o-aminothioamide. This is followed by condensation with DMF-HC1 to yield this amide (316) which then cyclizes to the product (317) [Pg.465]

Zirconium and hafnium dialkylamides are highly reactive compounds. They undergo (i) protolytic substitution reactions with reagents such as alcohols, cyclopentadiene and bis(trimethylsilyl)amine (ii) insertion reactions with CO2, CS2, COS, nitriles, phenyl isocyanate, methyl isothiocyanate, carbodiimides and dimethyl acetylenedicarboxylate and (iii) addition reactions with metal carbonyls. These reactions are summarized with reference to Zr(NMc2)4 in Scheme 1. 

A standard condition has been optimized for this reaction, in which the aryl amine is diazotized in 10 times its amount of acetic acid, followed by the addition of one equivalent of cuprous halide in hydrohalic acid. Under these conditions, the acetate salt of aryl amine is relatively soluble, and less froth and tarry material are formed during diazo transformation. In addition, chlorination, bromination, and iodonation of p-haloaniline to dihalobenzenes under such standard conditions give almost comparable average yields. Other modifications of this reaction include the formation of phenyl selenocyanate by the reaction with potassium selenocyanate, and aryl nitrile by the reaction with nickel cyanide. Moreover, this reaction has been extended to the preparation of phenyl thiocyanate, phenyl isothiocyanate and aromatic sulfonyl chloride. ... 

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