2-Aminophenol → 2H-1,4-benzoxazin-3(4H)-one

HRID 1732701Notes

Reaction equation

HRID 1732701 reaction equation
Cl[CH2:2][C:3](Cl)=[O:4].[NH2:6][C:7]1[CH:12]=[CH:11][CH:10]=[CH:9][C:8]=1[OH:13].C(=O)(O)[O-].[Na+].ClCC(N)=O>C(Cl)(Cl)Cl>[O:13]1[C:8]2[CH:9]=[CH:10][CH:11]=[CH:12][C:7]=2[NH:6][C:3](=[O:4])[CH2:2]1

Participants

6

Reactant 4

HCID 58012-AminophenolHCID 6577Chloroacetyl chlorideHCID 6580ChloroacetamideHCID 516892Sodium Bicarbonate

Product 1

HCID 727572H-1,4-benzoxazin-3(4H)-one

Reagents, catalysts & solvents 1

HCID 6212ChloroformSolvent

Procedure

Chloroacetyl chloride (104 g) is added slowly to a stirred mixture of o-aminophenol (96 g), sodium bicarbonate (100 g) and chloroform (1400 ml). After the addition is complete the reaction mixture is stirred at room temperature for 2 hours. The resulting chloroacetamide derivative, which separates in the course of the reaction, is filtered and added with stirring to 1 liter of NaOH, producing 2H-1,4-benzoxazin-3(4H)-one, which is filtered and washed with H2O, m.p. 169°-170°. The latter (30 g) is added portionwise to a suspension of 26 g of LiAlH4 in 1500 ml of anhydrous ether, keeping the temperature at 10° during the addition. After the addition is complete the reaction mixture is heated to reflux for 2 hours. It is then cooled, decomposed with water and filtered. The organic layer is separated and dried over anhydrous sodium sulfate; the solvent is removed in the rotary evaporator and the oily product obtained distilled to yield 3,4-dihydro-2H-1,4 -benzoxazine (b760 265°-267°). In a like manner as in Example 1, the latter benzoxazine is converted to the corresponding 4-nitroso derivative, which is worked up as described in Example 110 to give 4-amino-3,4-dihydro-2H-1,4-benzoxazine hydrochloride [m.p. 160° (dec.)] and finally the title compound m.p. 255° (dec.).

Workup

  1. additionAfter the addition
  2. filtrationis filtered
  3. additionadded
  4. stirringwith stirring to 1 liter of NaOH

Sources & evidence

ORD record
ord-22dd1a5caf314a8090bf742862fc64fb
Source dataset
uspto-grants-1980_12
Patent number
US04238607

Reaction notes

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