Water → 4-methyl-4H-pyrrolo[2,1-c][1,4]benzoxazine-4-acetic acid ethyl ester

HRID 259033Notes

Reaction equation

HRID 259033 reaction equation
[OH:1][C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][C:3]=1[N:8]1[CH:12]=[CH:11][CH:10]=[CH:9]1.[C:13]([O:19][CH2:20][CH3:21])(=[O:18])[CH2:14][C:15]([CH3:17])=O.C1(C)C=CC(S(O)(=O)=O)=CC=1.O>C1C=CC=CC=1>[CH2:20]([O:19][C:13](=[O:18])[CH2:14][C:15]1([CH3:17])[C:9]2=[CH:10][CH:11]=[CH:12][N:8]2[C:3]2[CH:4]=[CH:5][CH:6]=[CH:7][C:2]=2[O:1]1)[CH3:21]

Participants

6

Reactant 4

HCID 962WaterHCID 6101p-Toluenesulfonic acidHCID 8868Ethyl Acetoacetate2×HCID 7123342-(1H-Pyrrol-1-Yl)Phenol

Product 1

HCID 123406254-methyl-4H-pyrrolo[2,1-c][1,4]benzoxazine-4-acetic acid ethyl ester

Reagents, catalysts & solvents 1

HCID 241BenzeneSolvent

Procedure

A solution of the compound of formula 2, N-(2-hydroxyphenyl)pyrrole (5 g), described in Example 1, ethyl acetoacetate (4.3 g) and p-toluenesulfonic acid (0.5 g) in benzene (1,500 ml) is stirred and heated at reflux with a Dean-Stark water trap for 3 hr. Ethyl acetoacetate (1.0 g) is added and the reaction mixture kept under the refluxing condition overnight. After being cooled, the mixture is washed with a 5% solution of sodium bicarbonate and then water. The benzene solution is dried (MgSO4), filtered and evaporated. The crude product is purified by chromatography on a column of silica gel. Elution with chloroform gives 4-methyl-4H-pyrrolo[2,1-c][1,4]benzoxazine-4-acetic acid ethyl ester (3; R1 and R2 = H,R3 = CH3, n = 1, X = 0 and A = COOC2H5), νmaxCHCl3 1,725, 1,600, 1,505, 1,345, 1,080, 1,031 cm-1.

Workup

  1. temperatureheated
  2. customkept under the refluxing condition overnight
  3. temperatureAfter being cooled
  4. washthe mixture is washed with a 5% solution of sodium bicarbonate
  5. dry with materialThe benzene solution is dried (MgSO4)
  6. filtrationfiltered
  7. customevaporated
  8. customThe crude product is purified by chromatography on a column of silica gel
  9. washElution with chloroform

Sources & evidence

ORD record
ord-f5b3595a713c4748ae4abd805bf3620f
Source dataset
uspto-grants-1977_07
Patent number
US04035495

Reaction notes

Loading…