Hydrochloric Acid → 7-Chloro-2,3-dihydro-1,4-benzodioxine-5-carboxylic acid

HRID 1660010Notes

Reaction equation

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

Participants

Conditions

Temperature: 5 °C

Procedure

49 g of 7-amino-1,4-benzodioxane-5-carboxylic acid, 200 ml of water and 50 ml of hydrochloric acid were introduced into a balloon flask provided with an agitator and a thermometer. The mixture was cooled to 5° C. and then a solution of 17.5 g of sodium nitrite in 38 ml of water was added. The suspension was then poured into a solution of 20 g of cuprous chloride in 75 ml of hydrochloric acid. The precipitate was dried off, washed and dissolved in a solution of 42 g of sodium bicarbonate in 420 ml of water. The solution was filtered and treated with 100 ml of hydrochloric acid. 50 g of 7-chloro-1,4-benzodioxane-5-carboxylic acid was produced (M.P.: 180° C.; yield: 92.7%).

Workup

customprovided with an agitator
customThe precipitate was dried off
washwashed
dissolutiondissolved in a solution of 42 g of sodium bicarbonate in 420 ml of water
filtrationThe solution was filtered
additiontreated with 100 ml of hydrochloric acid

Sources & evidence

ORD record: ord-fdf568b6d4f74734840e7b66336ba27e
Source dataset: uspto-grants-1981_12
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US04306072

Reaction notes

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