Hydrochloric Acid → 7-Methoxy-1-oxo-1H-pyrimido[6,1-b]benzthiazole-4-carboxylic acid

HRID 224346Notes

Reaction equation

HRID 224346 reaction equation
COC1C=CC2N3C(=O)C(C(OCC)=O)=CN=C3SC=2C=1.[OH-].[Na+].Cl.[SH:25][C:26]1[CH:31]=[C:30]([O:32][CH3:33])[CH:29]=[CH:28][C:27]=1[N:34]1[C:39](=O)[C:38]([C:41]([OH:43])=[O:42])=[CH:37][NH:36][C:35]1=[O:44]>C(O)C>[CH3:33][O:32][C:30]1[CH:29]=[CH:28][C:27]2[N:34]3[C:35](=[O:44])[N:36]=[CH:37][C:38]([C:41]([OH:43])=[O:42])=[C:39]3[S:25][C:26]=2[CH:31]=1

Participants

6

Reactant 4

HCID 313Hydrochloric AcidHCID 14798Sodium HydroxideHCID 838855Ethyl 8-methoxy-4-oxopyrimido[2,1-b][1,3]benzothiazole-3-carboxylateHCID 233328051-(2-Mercapto-4-methoxyphenyl)-5-carboxypyrimidine-2,6-dione

Product 1

HCID 233327897-Methoxy-1-oxo-1H-pyrimido[6,1-b]benzthiazole-4-carboxylic acid

Reagents, catalysts & solvents 1

HCID 702EthanolSolvent

Procedure

4.5 g. Ethyl 8-methoxy-4-oxo-4H-pyrimido[2,1-b]-benzthiazole-3-carboxylate (prepared by the method described by Alaimo, J. Het. Chem., 10, 769/1973) are mixed with a mixture of 75 ml. 10% aqueous sodium hydroxide solution and 25 ml. ethanol and heated under reflux for 30 minutes. After neutralizing the reaction mixture with 2 N hydrochloric acid, 1-(2-mercapto-4-methoxyphenyl)-5-carboxypyrimidine-2,6-dione precipitates out. The yield is 3.5 g. (80% of theory); m.p. 266°-267° C. (decomp.).

Workup

  1. addition, 10, 769/1973) are mixed with a mixture of 75 ml
  2. temperatureunder reflux for 30 minutes
  3. customprecipitates out

Sources & evidence

ORD record
ord-9cd5f563df97405abd2db26ff91696b7
Source dataset
uspto-grants-1980_11
Patent number
US04232024

Reaction notes

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