6,7-Dibromo-8-nitro-2,3-dihydrobenzo[b][1,4]dioxine-5-carboxylic acid → 8-Amino-2,3-dihydrobenzo[b][1,4]dioxine-5-carboxylic acid

HRID 2052654Notes

Reaction equation

HRID 2052654 reaction equation
Br[C:2]1[C:11](Br)=[C:10]([N+:13]([O-])=O)[C:5]2[O:6][CH2:7][CH2:8][O:9][C:4]=2[C:3]=1[C:16]([OH:18])=[O:17].[H][H]>[Pd].O>[NH2:13][C:10]1[C:5]2[O:6][CH2:7][CH2:8][O:9][C:4]=2[C:3]([C:16]([OH:18])=[O:17])=[CH:2][CH:11]=1

Participants

5

Reactant 2

HCID 205447596,7-Dibromo-8-nitro-2,3-dihydrobenzo[b][1,4]dioxine-5-carboxylic acidHCID 178418361HCID 178418361, compound

Product 1

HCID 211934708-Amino-2,3-dihydrobenzo[b][1,4]dioxine-5-carboxylic acidYield 83.7%

Reagents, catalysts & solvents 2

HCID 23938PalladiumCatalystHCID 962WaterSolvent

Conditions

Temperature
50 °C

Procedure

400 ml of water, 98.5 g of 6,7-dibromo-8-nitro-1,4-benzodioxane-5-carboxylic acid, 100 ml of soda and 10 g of Pd/c were introduced into an autoclave and then hydrogen under a pressure of 40 kg/cm2 was introduced while heating to 50° C. The mixture was filtered and then treated with 95 ml of hydrochloric acid. The precipitate was dried off, washed and dried. 42 g of 8-amino-1,4-benzodioxane-5-carboxylic acid were obtained (M.P.: 186° C.; yield: 83.7%).

Workup

  1. filtrationThe mixture was filtered
  2. additiontreated with 95 ml of hydrochloric acid
  3. customThe precipitate was dried off
  4. washwashed
  5. customdried

Sources & evidence

ORD record
ord-17c671b8126d40d6816670f5f8fdb921
Source dataset
uspto-grants-1980_01
Patent number
US04186135

Reaction notes

Loading…