p-Toluenesulfonyl azide → HCID 178514330, compound

HRID 965324Notes

Reaction equation

HRID 965324 reaction equation
[OH:1][C:2]1[C:11]2[C:6](=[CH:7][CH:8]=[CH:9][CH:10]=2)[O:5][C:4](=[O:12])[CH:3]=1.C1(C)C=CC(S([N:22]=[N+:23]=[N-])(=O)=O)=CC=1>C1COCC1.C(N(CC)CC)C>[N+:22](=[C:3]1[C:2](=[O:1])[C:11]2[C:6](=[CH:7][CH:8]=[CH:9][CH:10]=2)[O:5][C:4]1=[O:12])=[N-:23]

Participants

5

Reactant 2

HCID 13661p-Toluenesulfonyl azideHCID 546829304-Hydroxycoumarin2×

Product 1

HCID 178514330HCID 178514330, compoundYield 70.6%

Reagents, catalysts & solvents 2

HCID 8028TetrahydrofuranSolvent2×HCID 8471TriethylamineSolvent

Procedure

To a 100 mL round-bottom flask fitted with a mechanical stirrer, nitrogen inlet and bubbler was charged 4-hydroxycoumarin (3.1 g, 18.8 mmol) dissolved in dry THF (21.6 g) and triethylamine (1.8 g). A solution of p-toluenesulfonyl azide (5.3 g, 28.3 mmol) in dry THF (14.4 g) was then added to this solution dropwise over a period of 15 minutes. The reaction was continued until all of 4-hydroxycoumarin had reacted as monitored by HPLC (ca. 2.0 hours). The precipitated reaction product was filtered on a small Buchner funnel and the filtrate was packed in powdered dry ice to produce a second crop of crystals which were also isolated by filtration. The combined filtercakes were dried overnight under vacuum at 60° C. to obtain orange colored crystals of 3-diazo-4-oxo-3,4-dihydrocoumarin; yield 2.5 g (70.6% yield). The crude product was further purified by dissolving it in 75.0 g of acetone and precipitating by pouring into 150.0 g ice-water yielding pale yellow crystals. The product was characterized by 13C NMR, and DSC. A sample recrystallized from acetone-water melted at 159.5° C.; 13C-NMR in DMSO-d6 solvent showed 9 singlet lines at the following chemical shifts, in ppm: 173.748, 157.754, 153.316, 136.239, 125.231, 125.063, 118.696, 117.741, 77.022.

Workup

  1. customTo a 100 mL round-bottom flask fitted with a mechanical stirrer, nitrogen inlet
  2. customhad reacted
  3. customas monitored by HPLC (ca. 2.0 hours)
  4. customThe precipitated reaction product
  5. filtrationwas filtered on a small Buchner funnel
  6. customto produce a second crop of crystals which
  7. customwere also isolated by filtration
  8. customThe combined filtercakes were dried overnight under vacuum at 60° C.

Sources & evidence

ORD record
ord-4d92b3045afe4e9194d034e7a95f2350
Source dataset
uspto-grants-1998_06
Patent number
US05773591

Reaction notes

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