Diazomethane → 2-Methyl-1,2,3-benzotriazole

HRID 366426Notes

Reaction equation

HRID 366426 reaction equation
[NH:1]1[C:5]2[CH:6]=[CH:7][CH:8]=[CH:9][C:4]=2[N:3]=[N:2]1.[N+:10](=[CH2:12])=[N-:11]>C(Cl)Cl>[CH3:12][N:2]1[N:3]=[C:4]2[CH:9]=[CH:8][CH:7]=[CH:6][C:5]2=[N:1]1.[CH3:12][N:10]1[C:4]2[CH:9]=[CH:8][CH:7]=[CH:6][C:5]=2[N:1]=[N:11]1

Participants

5

Reactant 2

HCID 9550DiazomethaneHCID 178418385HCID 178418385, compound

Product 2

HCID 259021-MethylbenzotriazoleYield 15%HCID 854982-Methyl-1,2,3-benzotriazoleYield 36%

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent

Procedure

Benzotriazole free base (from above; 155 mg, 0.36 mmol) in CH2Cl2 (2.5 mL) was treated while stirring with etheral diazomethane (2-10 eq.). After about 2 h (10-20° C.) the solvent and excess diazomethane were removed in vacuo and the residue was chromatographed on silica (Chromatotron; 1% conc. NH4OH; 1.5% MeOH, 97.5% (CHCl3)) to afford (36%; 57 mg) 2-N-methyl benzotriazole derivative (Example 169) and (15%; 24 mg) 3-N-methyl benzotriazole (Example 168).

Workup

  1. customAfter about 2 h (10-20° C.) the solvent and excess diazomethane were removed in vacuo
  2. customthe residue was chromatographed on silica (Chromatotron; 1% conc. NH4OH; 1.5% MeOH, 97.5% (CHCl3))

Sources & evidence

ORD record
ord-cd17d1db534444bf9755612a24e1b946
Source dataset
uspto-grants-2000_10
Patent number
US06130217

Reaction notes

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