Ethanol → 4,5-Dihydro-2-methyl-8-methylthiothieno[3,4-e]benzothiazole-6-carboxylic acid
Reaction equation
[CH3:1][C:2]1[S:3][C:4]2[CH2:10][CH2:9][C:8]3=[C:11]([C:16]([O:18]CC)=[O:17])[S:12][C:13]([S:14][CH3:15])=[C:7]3[C:5]=2[N:6]=1.C(O)C.O1CCCC1.[OH-].[Na+]>O>[CH3:1][C:2]1[S:3][C:4]2[CH2:10][CH2:9][C:8]3=[C:11]([C:16]([OH:18])=[O:17])[S:12][C:13]([S:14][CH3:15])=[C:7]3[C:5]=2[N:6]=1Participants
Reactant 4
Product 1
Reagents, catalysts & solvents 1
Procedure
Ethyl 4,5-dihydro-2-methyl-8-methylthiothieno[3,4-e]benzothiazole-6-carboxylate (0.76 g) was suspended in a mixed solvent of ethanol (10 ml) and tetrahydrofuran (25 ml); a 2 N aqueous solution of sodium hydroxide (2.3 ml) was added at room temperature. After the reaction mixture was stirred at room temperature for 1 hour, the solution obtained was diluted with water (30 ml) and washed with diethyl ether. The water layer was acidified with 1 N hydrochloric acid (5 ml) and extracted with a mixed solvent of ethyl acetate and tetrahydrofuran. The ethyl acetate-tetrahydrofuran layer was washed with water and dried (MgSO4), after which the solvent was distilled off to yield 4,5-dihydro-2-methyl-8-methylthiothieno[3,4-e]benzothiazole-6-carboxylic acid (0.35 g, 50%), which was then recrystallized from ethyl acetate-hexane. Brown prisms. Melting point 273-274° C.
Workup
- customthe solution obtained
- washwashed with diethyl ether
- extractionextracted with a mixed solvent of ethyl acetate and tetrahydrofuran
- washThe ethyl acetate-tetrahydrofuran layer was washed with water
- dry with materialdried (MgSO4)
- distillationafter which the solvent was distilled off
Sources & evidence
- ORD record
- ord-b7b8a0b234114aaeb20e19fc9799923b
- Source dataset
- uspto-grants-2000_05
- Patent number
- US06066658
Reaction notes
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