4-nitrotoluene

 

4-nitrotoluene

Chemical formula	C7H7NO2
OTP appearance	pale yellow crystals
Molar Mass(g/mol)	137.14
Melting Point(°C)	51.63
Boiling Point(°C)	238.3
Solubility in water(g/L)	40
NFPA 704	1 3 1

Uses

Justification Questioned

Other

• Precursor to 4-aminobenzoic acid (PABA)

Natural occurrence

• does not occur naturally

Hazards

• Extremely sensitive explosive, vasodialator

Production

Synthesis

1. Produce a cool nitration mixture by combining 105ubm (68%) nitric acid and 165ubm 98% sulfuric acid (1.14:1.69 molar ratio)
2. Add the nitration mixture dropwise to 67.86ubm of toluene in a cooling bath, keeping the solution below 15°C

   C₇H₈ + HNO₃

   {H₂SO₄

   →

   2h}

   C₇H₇NO₂ + H₂O

3. Continue to stir while temperature rises to room temperature over 1h.
4. Use a separatory funnel to remove the mixed acid (lower) layer
5. Neutralize the acid and discard.
6. Wash the nitrotoluene with distilled water.
7. Separate the aqueous (top) layer
8. discard aqueous layer
9. Wash with saturated sodium bicarbonate solution
10. Separate and discard aqueous (top) layer
11. Discard aqueous layer

    NB Remainder (nitrotoluene layer) should be opaque milky yellow-orange color slurry

12. Allow to stand
13. Discard any aqueous supernatant
14. Dry over calcium chloride
15. Allow to stand
16. filter
17. discard residue (hydrated calcium chloride)

    NB the filtrate (nitrotoluene mixture) should now be clear yellow fluid

18. repeat
    1. Freeze below -10°C
    2. warm to -10°C

       NB 2- and 3- nitrotoluene are liquid at -10, 4-nitrotoluene is solid

    3. Vacuum filter.
    4. Residue is 4-nitrotoluene. Retain.
    5. Filtrate is mixture of 2- and 3-nitrotoluene. Retain or discard.
19. until all the 4-nitrotoluene is extracted from the mixture.