Water → 3-Oxo-3,4-dihydro-2H-pyrido[3,2-b][1,4]thiazine-6-carboxylic acid
Reaction equation
[O:1]=[C:2]1[CH2:7][S:6][C:5]2[CH:8]=[CH:9][C:10]([C:12]([O:14]C)=[O:13])=[N:11][C:4]=2[NH:3]1.O.[OH-].[Na+]>O1CCOCC1>[O:1]=[C:2]1[CH2:7][S:6][C:5]2[CH:8]=[CH:9][C:10]([C:12]([OH:14])=[O:13])=[N:11][C:4]=2[NH:3]1Participants
5
Procedure
A solution of methyl 3-oxo-3,4-dihydro-2H-pyrido[3,2-b][1,4]thiazine-6-carboxylate (788 mg) in dioxane (120 ml)/water (30 mL) was treated dropwise over 2 h with 0.5M NaOH solution (8 mL) and stirred overnight. After evaporation to approx. 3 ml, water (5 mL) was added and 2M HCl to pH4. The precipitated solid was filtered off, washed with a small volume of water and dried under vacuum to give a solid (636 mg); LC/MS (APCI−) m/z 209 ([M−H]−, 5%), 165([M-COOH]−, 100%).
Workup
- customAfter evaporation to approx. 3 ml, water (5 mL)
- additionwas added
- filtrationThe precipitated solid was filtered off
- washwashed with a small volume of water
- customdried under vacuum
Sources & evidence
- ORD record
- ord-e7e75db7cd6a460dbb99c4f2e3a3cfaf
- Source dataset
- uspto-grants-2009_09
- Patent number
- US07592334B2
Reaction notes
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