Sulfuric Acid → (5,6-Dimethyl-3-oxo-2-benzofuran-1(3H)-ylidene)acetonitrile

HRID 437841Notes

Reaction equation

HRID 437841 reaction equation
[N:1]([C:4]1[C:5]([C:7]2[C:12]([C:13](=[O:15])[CH:14]=1)=[CH:11][C:10]([CH3:16])=[C:9]([CH3:17])[CH:8]=2)=[O:6])=[N+]=[N-].S(=O)(=O)(O)O.C1(C2C(=CC=CC=2)CO1)=O>>[C:4]([CH:14]=[C:13]1[C:12]2[C:7](=[CH:8][C:9]([CH3:17])=[C:10]([CH3:16])[CH:11]=2)[C:5](=[O:6])[O:15]1)#[N:1]

Participants

4

Reactant 3

HCID 1118Sulfuric AcidHCID 6885PhthalideHCID 123664042-Azido-6,7-dimethylnaphthalene-1,4-dione

Product 1

HCID 54010491(5,6-Dimethyl-3-oxo-2-benzofuran-1(3H)-ylidene)acetonitrile

Conditions

Temperature
3 °C

Procedure

2-Azido-6,7-dimethyl naphtho-1,4-quinone (2.0 g) was added in small portions (10 mg) to cold (0°-5° C.), vigorously stirred concentrated sulphuric acid (30 ml. over 11/2 hours and the red solution stirred a further 10 minutes at 3° C. until nitrogen evolution ceased. Poured onto ice-water (400 g) whereby the phthalide separated as a whitish solid. After recrystallisation from ethanol in the presence of charcoal the white solid had m.p. 165°-181° C. (mixture of E and Z isomers). (Found; C, 72.10; H, 4.77; N, 6.91; C12H9NO2 requires; C, 72.35; H, 4.55; N, 7.03%).

Workup

  1. customseparated as a whitish solid
  2. customAfter recrystallisation from ethanol in the presence of charcoal the white solid
  3. additionm.p. 165°-181° C. (mixture of E and Z isomers)

Sources & evidence

ORD record
ord-22dea0a22e7b4c5f92761e4af750b3bf
Source dataset
uspto-grants-1977_06
Patent number
US04032544

Reaction notes

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