Sodium Nitrite → HCID 178497407, compound

HRID 906100Notes

Reaction equation

HRID 906100 reaction equation
[NH2:1][C:2]1[C:3]([CH3:13])=[C:4]([CH:9]=[CH:10][C:11]=1[NH2:12])[C:5]([O:7][CH3:8])=[O:6].[N:14]([O-])=O.[Na+]>S(=O)(=O)(O)O>[CH3:13][C:3]1[C:2]2[NH:1][N:14]=[N:12][C:11]=2[CH:10]=[CH:9][C:4]=1[C:5]([O:7][CH3:8])=[O:6]

Participants

4

Reactant 2

HCID 23668193Sodium Nitrite2×HCID 67403564Methyl 3,4-diamino-2-methylbenzoate

Product 1

HCID 178497407HCID 178497407, compoundYield 104.6%

Reagents, catalysts & solvents 1

HCID 1118Sulfuric AcidSolvent2×

Conditions

Temperature
0 °C

Procedure

Methyl 3,4-diamino-2-methylbenzoate (0.27 g, 1.5 mmol) was taken up in concentrated sulfuric acid (30 mL) and heated to solubilize, then cooled with an ice bath. Concurrently, sodium nitrite (0.14 g, 2.1 mmol) was solubilized in concentrated sulfuric acid (8.4 mL) using heating. This sodium nitrite solution was then cooled and added dropwise to the cooled solution of diamine. The mixture was stirred at 0° C. for 30 minutes then warmed to 60° C. for 15 minutes. The solution was then poured onto ice and extracted with 10% methanol in ethyl acetate (2×100 mL). The combined organic layers were dried (magnesium sulfate), filtered and concentrated to give 0.3 g of crude methyl 7-methyl-1H-benzotriazole-6-carboxylate, which was taken up in methanol (5 mL) and tetrahydrofuran (10 mL) and treated with 2M aqueous lithium hydroxide (5 mL), then heated to 70° C. for one hour. This solution was made acidic using concentrated aqueous hydrochloric acid, then extracted with 10% methanol in ethyl acetate (2×50 mL). The combined organic layers were dried (magnesium sulfate), filtered and concentrated to give 0.26 g of 7-methyl-1H-benzotriazole-6-carboxylic acid. 1H NMR (400 MHz, d6-DMSO): 7.94 (d, 1H), 7.72 (m, 1H), 2.95 (s, 3H). MS (EI) for C8H7N3O2: 178 (MH+).

Workup

  1. temperatureheated
  2. temperaturecooled with an ice bath
  3. temperatureusing heating
  4. temperaturethen warmed to 60° C. for 15 minutes
  5. additionThe solution was then poured onto ice
  6. extractionextracted with 10% methanol in ethyl acetate (2×100 mL)
  7. dry with materialThe combined organic layers were dried (magnesium sulfate)
  8. filtrationfiltered
  9. concentrationconcentrated

Sources & evidence

ORD record
ord-bc1f7070877446719b34161faaaf1960
Source dataset
uspto-grants-2011_09
Patent number
US08012956B2

Reaction notes

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