3-Methyl-2-butenoic acid → 1-(1H-1,2,3-Benzotriazol-1-yl)-3-methylbut-2-en-1-one

HRID 240481Notes

Reaction equation

HRID 240481 reaction equation
[NH:1]1[C:5]2[CH:6]=[CH:7][CH:8]=[CH:9][C:4]=2[N:3]=[N:2]1.S(Cl)(Cl)=O.[CH3:14][C:15]([CH3:20])=[CH:16][C:17](O)=[O:18]>ClCCl>[N:1]1([C:17](=[O:18])[CH:16]=[C:15]([CH3:20])[CH3:14])[C:5]2[CH:6]=[CH:7][CH:8]=[CH:9][C:4]=2[N:3]=[N:2]1

Participants

5

Reactant 3

HCID 109313-Methyl-2-butenoic acidHCID 24386Thionyl ChlorideHCID 178418385HCID 178418385, compound

Product 1

HCID 267930961-(1H-1,2,3-Benzotriazol-1-yl)-3-methylbut-2-en-1-oneYield 90%

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent

Procedure

1H-Benzotriazole (2.14 g, 18.0 mmol, 4 equiv.) was dissolved in dichloromethane (25 ml) and thionyl chloride (330 μl, 4.5 mmol, 1 equiv.) was added at room temperature. (450 mg, 4.5 mmol) 3-Methyl-but-2-enoic acid [CAS 541-47-9] was added and the mixture was stirred for 2 hours at room temperature. The suspension was filtered and the filtrate was extracted once with 2N NaOH solution and twice with dichloromethane. The organic extracts were combined, dried over sodium sulfate and evaporated to dryness. The crude product was purified by flash chromatography on a silica gel column eluting with an ethyl acetate:cyclohexane gradient 0:100 to 50:50. The desired 1-benzotriazol-1-yl-3-methyl-but-2-en-1-one (810 mg, 90% yield) was obtained as a light yellow solid, MS: m/e=202.1 (M+H+).

Workup

  1. filtrationThe suspension was filtered
  2. extractionthe filtrate was extracted once with 2N NaOH solution and twice with dichloromethane
  3. dry with materialdried over sodium sulfate
  4. customevaporated to dryness
  5. customThe crude product was purified by flash chromatography on a silica gel column
  6. washeluting with an ethyl acetate

Sources & evidence

ORD record
ord-0ef0089cf5934bfcaf6c679ad3464802
Source dataset
uspto-grants-2014_02
Patent number
US08648088B2

Reaction notes

Loading…