Hydrochloric Acid → 4,4'-Diazenediyldianiline

HRID 1526762Notes

Reaction equation

HRID 1526762 reaction equation
C([NH:4][C:5]1[CH:10]=[CH:9][C:8]([N:11]=[N:12][C:13]2[CH:18]=[CH:17][C:16]([NH:19]C(=O)C)=[CH:15][CH:14]=2)=[CH:7][CH:6]=1)(=O)C.Cl>CO>[NH2:19][C:16]1[CH:15]=[CH:14][C:13]([N:12]=[N:11][C:8]2[CH:9]=[CH:10][C:5]([NH2:4])=[CH:6][CH:7]=2)=[CH:18][CH:17]=1

Participants

4

Reactant 2

HCID 313Hydrochloric AcidHCID 27289Acetamide, N,N'-(azodi-4,1-phenylene)bis-

Product 1

HCID 108554,4'-DiazenediyldianilineYield 76.8%

Reagents, catalysts & solvents 1

HCID 887MethanolSolvent

Procedure

Without further purification, 4,4′-bis(acetamido)azobenzene (II) (16.0 g, 0.054 mol) is placed in a 500-mL round-bottomed flask equipped with a condenser and a magnetic stirrer, along with methanol (150 mL) and 6N hydrochloric acid (150 mL). The mixture is heated under reflux for 1.5 hours. The reaction mixture is cooled, and the violet solid is collected on a Büchner funnel. The mixture is heated under reflux for 1.5 hours. The reaction mixture is cooled, and the violet solid collected on a Büchner funnel. The damp product is suspended in 500 mL of water in a 1 L beaker equipped with a stirrer, and the mixture is slowly neutralized by the addition of 2.5N sodium hydroxide, during which the salt dissolves and the free base separates. The crude product is collected on a Büchner funnel, washed with water, and dried under reduced pressure. The yellow powder is then recrystallized from N-methylpyrrolidinone to afford yellow crystals of DAAB (III) (8.8 g, 42%), m.p. 244.5-247.9° C. (dec.). FT-IR (KBr, cm−1): 3417, 3333, 3212 (NH2), 3040, 1627, 1592, 1502, 1294, 1150, 839. 1H-NMR (DMSO-d6, δ in ppm): 5.72 (s, 4H, NH2), 6.61-6.63 (d, 4H, Ar—H), 7.51-7.53 (d, 4H, Ar—H). 13C-NMR (DMSO-d6, δ in ppm): 113.4, 123.7, 143.1, 150.9. Purification of (III) by column chromatography met with limited success due to its poor solubility in most organic solvents.

Workup

  1. customis placed in a 500-mL round-bottomed flask
  2. temperatureThe mixture is heated
  3. temperatureunder reflux for 1.5 hours
  4. temperatureThe reaction mixture is cooled
  5. customthe violet solid is collected on a Büchner funnel
  6. temperatureThe mixture is heated
  7. temperatureunder reflux for 1.5 hours
  8. temperatureThe reaction mixture is cooled
  9. customthe violet solid collected on a Büchner funnel
  10. custombeaker equipped with a stirrer
  11. additionthe mixture is slowly neutralized by the addition of 2.5N sodium hydroxide, during which the salt
  12. dissolutiondissolves
  13. customThe crude product is collected on a Büchner funnel
  14. washwashed with water
  15. customdried under reduced pressure
  16. customThe yellow powder is then recrystallized from N-methylpyrrolidinone

Sources & evidence

ORD record
ord-39aff12e594041cdb43edced3650a901
Source dataset
uspto-grants-2015_07
Patent number
US09085661B1

Reaction notes

Loading…