Thiourea → Ethyl 2-methoxyimino-2-(2-aminothiazol-4-yl)acetate hydrobromide

HRID 1065905Notes

Reaction equation

HRID 1065905 reaction equation
[CH3:1][O:2][N:3]=[C:4]([C:10]([CH2:12][Br:13])=O)[C:5]([O:7][CH2:8][CH3:9])=[O:6].[NH2:14][C:15]([NH2:17])=[S:16]>C(O)C>[BrH:13].[CH3:1][O:2][N:3]=[C:4]([C:10]1[N:14]=[C:15]([NH2:17])[S:16][CH:12]=1)[C:5]([O:7][CH2:8][CH3:9])=[O:6]

Participants

4

Reactant 2

HCID 2723790ThioureaHCID 54053279Butanoic acid, 4-bromo-2-(methoxyimino)-3-oxo-, ethyl ester

Product 1

HCID 73668749Ethyl 2-methoxyimino-2-(2-aminothiazol-4-yl)acetate hydrobromide

Reagents, catalysts & solvents 1

HCID 702EthanolSolvent

Procedure

A solution of ethyl 2-methoxyimino-4-bromoacetoacetate (a mixture of syn and anti isomers) (17.4 g.) and thiourea (5.4 g.) in ethanol (100 ml.) was refluxed for 4 hours. The reaction mixture was allowed to stand and cooled in refrigerator to precipitate crystals. The crystals were collected by filtration, washed with ethanol and dried to give ethyl 2-methoxyimino-2-(2-amino-1,3-thiazol-4-yl)acetate hydrobromide (anti isomer) (9.5 g.). The filtrate and the washings were put together and concentrated under reduced pressure. Water (100 ml.) was added to the residue and the mixture was washed with ether. The aqueous layer was alkalized with a 28% aqueous solution of ammonia and extracted with ethyl acetate. The extract was washed with water and a saturated sodium chloride aqueous solution and dried over magnesium sulfate. The solvent was distilled off under reduced pressure to give crystalline substance of ethyl 2-methoxyimino-2-(2-amino-1,3-thiazol-4-yl)acetate (syn isomer) (5.2 g.).

Workup

  1. temperaturewas refluxed for 4 hours
  2. temperaturecooled in refrigerator
  3. customto precipitate crystals
  4. filtrationThe crystals were collected by filtration
  5. washwashed with ethanol
  6. customdried

Sources & evidence

ORD record
ord-b5a2f53a6d5e4221866a0a242bc7111b
Source dataset
uspto-grants-1982_05
Patent number
US04331664

Reaction notes

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