Hydrochloric Acid → 2-(Isothiazol-4-yl)glyoxylic acid

HRID 463927Notes

Reaction equation

HRID 463927 reaction equation
ON=[C:3]([C:8]1[CH:9]=[N:10][S:11][CH:12]=1)[C:4]([O:6]C)=[O:5].C=[O:14].Cl>O>[S:11]1[CH:12]=[C:8]([C:3](=[O:14])[C:4]([OH:6])=[O:5])[CH:9]=[N:10]1

Participants

5

Reactant 3

HCID 313Hydrochloric AcidHCID 712FormaldehydeHCID 57310772Methyl 2-hydroxyimino-2-(isothiazol-4-yl)acetate

Product 1

HCID 129065552-(Isothiazol-4-yl)glyoxylic acid

Reagents, catalysts & solvents 1

HCID 962WaterSolvent

Procedure

A mixture of methyl 2-hydroxyimino-2-(isothiazol-4-yl)-acetate (anti isomer) (3.41 g.), 36% aqueous solution of formaldehyde (24 ml.), conc. hydrochloric acid (12 ml.) and water (24 ml.) was stirred for 7 hours at 90° to 100° C. The reaction mixture was allowed to stand overnight in a refrigerator to precipitate crystals. The crystals were collected by filtration, washed with a small amount of ice-water and then dried to give 2-(isothiazol-4-yl)glyoxylic acid (2.09 g.). The mother liquor was extracted with ethyl acetate to give the same compound (0.34 g.), mp 145° to 148° C.

Workup

  1. waitto stand overnight in a refrigerator
  2. customto precipitate crystals
  3. filtrationThe crystals were collected by filtration
  4. washwashed with a small amount of ice-water
  5. customdried

Sources & evidence

ORD record
ord-0615026e03ca4919af64fac0b22483a3
Source dataset
uspto-grants-1985_10
Patent number
US04544751

Reaction notes

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