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Ammonia


Other Names:

Azane







General Information:


Structure:



CAS Number: 7664-41-7

Molecular Weight: 17.031 g/mol

Appearance: Colorless gas

Chemical Formula: NH3

Melting Point: -78 C

Boiling Point: -33 C

Acidity (Pka): 32.5

Basicity (Pkb): 4.75


Ammonia (NH3) has a strong pungent odor. It is a gas at room temperature and is lighter than air. Ammonia is often stored as a liquid in high pressure tanks. In organic chemistry labs ammonia is often used in other, more easy to handle forms. For example, liquid sources of ammonia are ammonium hydroxide (NH4OH) and ammonia in MeOH (typically 2N or 7N). The most common solid source of ammonia is ammonium chloride (NH4Cl).




Common Uses:


(The examples include ammonia in its commonly used forms: NH4OH, NH3 in MeOH, and NH4Cl)


Reagent in amide couplings





Reagent in amide formation reactions with acid chlorides





Reagent in substitution reactions





Reagent in SNAr reactions





Reagent in reductive aminations





Additive in the catalytic reduction of nitriles





Additive in silica gel chromatography



Procedure excerpt:
…concentrated in vacuo. The resulting crude material was purified by chromatography [330 g SiO2, 0-5% (10% NH4OH in MeOH)/(DCM)] to provide…




Additive in reverse phase chromatography



Procedure excerpt:
…heated with shaking at 90 C overnight. The crude solution was purified by reverse phase chromatography (C18, 5-95% ACN/H2O, 0.1% NH4OH) to provide…




Safety:


Mixing ammonia containing compounds (ex. NH3, NH4OH, or NH4Cl) and bleach (NaOCl) is very dangerous because it produces toxic by-pdts. People have died from mixing cleaning supplies that contain ammonia and bleach. Household cleaning products that contain ammonia are typically aqueous solutions (NH4OH).




References:


1) WO2014149164, page 227

2) WO2012149280, page 72

3) WO2016014463, page 91

4) WO2015084384, page 62

5) WO2015051043, page 127

6) Wikipedia: Ammonia (link)

7) www.sigmaaldrich.com: Ammonia (link)

8) The Chlorine Institute, Sodium Hypochlorite Incompatibility Chart (link)