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I found a way to produce Secondary Alkyl Amines using Grignard Reagent.

Grignard to R-NH-R1
(source: wiley.com)

Ref: Z. Huang, J. Lv, Y. Jia, Chemistry Select 2016, 1, 5892. DOI: 10.1002/slct.201601464

But I want to know if I can use $\ce{HNO2}$ instead of $\ce{R-NO2}$ here to obtain $\ce{R^1-NH2}$ [say, $\ce{H-NH-R^1}$] or is there any other way to produce Primary Amines ($\ce{R-NH2}$) using Grignard Reagent ($\ce{R-Mg-X}$)?

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2 Answers 2

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Grignard reagents, in addition to being nucleophiles, are strong bases. Attempting to react a Grignard $\ce{RMgX}$ with nitrous acid is simply going to result in protonation of the Grignard to give $\ce{R-H}$ and magnesium nitrite.

Primary amines can be prepared from Grignard by reaction with 1,3-dioxolan-2-one O-sulfonyloxime.

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Ref: Synthesis of Primary Amines by the Electrophilic Amination of Grignard Reagents with 1,3-Dioxolan-2-one O-Sulfonyloxime Mitsuru Kitamura, Takahiro Suga, Shunsuke Chiba, and Koichi Narasaka Organic Letters 2004 6 (24), 4619-4621 DOI: 10.1021/ol0479951

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Yes indeed. Primary amines can be made using Grignard reagent. The first reported instances of such reaction was found during the 1930s where they used mono/dihaloamines and reacted with Grignard reagent to form primary amine, secondary amine and other side products like ammonia and mixed magnesium halide reaction (Ref.1a).

$$\ce{RMgX + NH2Cl -> RNH2 + MgXCl + (other side products)}$$ $$\ce{RMgX + NH2Cl -> RCl + MgXNH2 (side reaction)}$$

When dihaloamines is used, the yields are not that promising (Ref.1b):

Dibromoamine reacts with Grignard reagents to produce primary amines, secondary amines, ammonia, and nitrogen. The percentage yields of these products if Grignard reagent used is n-butyl magnesium chloride are n-butylamine 7.8 per cent, di-n-butylamine 2.2 per cent, ammonia 79.0 per cent, nitrogen 5.9 per cent;

There are tons of other electrophilic aminating agent beside one mentioned in Waylander's answer. Some examples being 4,4′-Bis(trifluoromethyl)benzophenone O-sulfonyloximes (Ref.2a), 2-Imidazolidinone O-sulfonyloxime (Ref. 2b). You can find tons of other reaction which uses Grignard agent to produce amines. (Ref. 3)

References

  1. The formation of primary amines from Grignard reagent by George H. Coleman and Charles B. Yager:
  2. Preparation of Primary Amines from Grignard reagents by Koichi et.al.
  3. Synthesis of amines by the electrophilic amination of organomagnesium, -zinc, -copper, and -lithium reagents by Tahir Daşkapan, DOI: 10.3998/ark.5550190.0012.520
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    $\begingroup$ Thanks a lot, brother. Most of the references are of limited access, unfortunately. Yet, the answer is very helpful. Particularly, Ref. 3 is very informative and it fulfills the shortcoming of the other links. Ref. 1a is also helpful. Again, thanks. $\endgroup$ Jun 9, 2022 at 6:07
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    $\begingroup$ @KMFRuhan if you are happy with the answers please accept them $\endgroup$
    – Waylander
    Jun 9, 2022 at 6:50

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