Hydrochloric Acid → 8-Chloro-2,3-dihydro-1,4-benzodioxin-5-carboxylic acid

HRID 127437Notes

Reaction equation

HRID 127437 reaction equation
N[C:2]1[C:7]2[O:8][CH2:9][CH2:10][O:11][C:6]=2[C:5]([C:12]([OH:14])=[O:13])=[CH:4][CH:3]=1.N([O-])=O.[Na+].[ClH:19]>O>[Cl:19][C:2]1[C:7]2[O:8][CH2:9][CH2:10][O:11][C:6]=2[C:5]([C:12]([OH:14])=[O:13])=[CH:4][CH:3]=1

Participants

5

Reactant 3

HCID 313Hydrochloric Acid2×HCID 211934708-Amino-2,3-dihydrobenzo[b][1,4]dioxine-5-carboxylic acidHCID 23668193Sodium Nitrite

Product 1

HCID 233670468-Chloro-2,3-dihydro-1,4-benzodioxin-5-carboxylic acidYield 62%

Reagents, catalysts & solvents 1

HCID 962WaterSolvent2×

Conditions

Temperature
40 °C

Procedure

29.3 g of 8-amino-1,4-benzodioxane-5-carboxylic acid, 120 ml of water and 30 ml of hydrochloric acid were introduced into a balloon flask provided with an agitator and a thermometer. The mixture was heated to 40° C. and then cooled to 5° C. and a solution of 10.5 g of sodium nitrite in 20 ml of water was added in portions with the temperature being maintained at from 5°-10° C. The mixture was agitated and then poured into a solution of 12 g of cuprous chloride in 45 ml of hydrochloric acid (d=1.18) with the temperature being maintained below 30° C. The precipitate was dried off, washed in 300 ml of water and 25 g of sodium bicarbonate. The solution was filtered and treated with hydrochloric acid. The precipitate was dried off, washed with water and dried. 20 g of 8-chloro-1,4-benzodioxane-5-carboxylic acid were obtained (M.P.: 195° C.; yield: 62%).

Workup

  1. customprovided with an agitator
  2. temperaturecooled to 5° C.
  3. temperaturebeing maintained at from 5°-10° C
  4. temperaturebeing maintained below 30° C
  5. customThe precipitate was dried off
  6. washwashed in 300 ml of water
  7. filtrationThe solution was filtered
  8. additiontreated with hydrochloric acid
  9. customThe precipitate was dried off
  10. washwashed with water
  11. customdried

Sources & evidence

ORD record
ord-28429fa067de447d965b3f3ac7ff4edc
Source dataset
uspto-grants-1981_03
Patent number
US04255580

Reaction notes

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