Sodium Hydroxide → 1H,2H,4H-thieno(3,2-d)(1,3)oxazine-2,4-dione

HRID 223322Notes

Reaction equation

HRID 223322 reaction equation
Cl.[NH2:2][C:3]1[CH:7]=[CH:6][S:5][C:4]=1[C:8]([O:10][CH3:11])=[O:9].[OH-:12].[Na+]>C(O)CCC>[NH:2]1[C:3]2[CH:7]=[CH:6][S:5][C:4]=2[C:8](=[O:9])[O:10][C:11]1=[O:12]

Participants

4

Reactant 2

HCID 14798Sodium HydroxideHCID 12517407Methyl 3-amino-2-thiophenecarboxylate hydrochloride

Product 1

HCID 27775521H,2H,4H-thieno(3,2-d)(1,3)oxazine-2,4-dione

Reagents, catalysts & solvents 1

HCID 2631-ButanolSolvent

Procedure

A mixture of 175 g (0.93 mol) of methyl 3-amino-2-thiophenecarboxylate hydrochloride, 1.8 l of n-butanol and 77 g of sodium hydroxide is heated to boiling under reflux for 30 minutes and the suspension obtained is concentrated. The resulting mixture of the sodium salt of 3-amino-2-thiophenecarboxylic acid and sodium chloride is treated with 800 ml of water, 280 ml of concentrated hydrochloric acid and 230 ml of tetrahydrofuran and at 15° to 25° phosgene is conducted through this mixture for 2.5 hours and subsequently air is conducted through the mixture for 15 minutes. The precipitated solid material is filtered off under suction, washed with water and dried. There is obtained 2H-thieno[3,2-d][1,3]oxazine-2,4(1H)-dione of melting point 220°-221°.

Workup

  1. temperatureis heated
  2. temperatureunder reflux for 30 minutes
  3. customthe suspension obtained
  4. concentrationis concentrated
  5. additionThe resulting mixture of the sodium salt of 3-amino-2-thiophenecarboxylic acid and sodium chloride
  6. additionis treated with 800 ml of water, 280 ml of concentrated hydrochloric acid and 230 ml of tetrahydrofuran and at 15° to 25° phosgene
  7. waitsubsequently air is conducted through the mixture for 15 minutes
  8. filtrationThe precipitated solid material is filtered off under suction
  9. washwashed with water
  10. customdried

Sources & evidence

ORD record
ord-ee9917087a23405dbec512eae1b68b10
Source dataset
uspto-grants-1982_10
Patent number
US04353827

Reaction notes

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