ChemicalBook CAS DataBase List 6-Benzothiazolecarboxylicacid,2,3-dihydro-2-oxo-(9CI)

6-Benzothiazolecarboxylicacid,2,3-dihydro-2-oxo-(9CI) synthesis

9synthesis methods

Product Name:6-Benzothiazolecarboxylicacid,2,3-dihydro-2-oxo-(9CI)
CAS Number:99615-68-6
Molecular formula:C8H5NO3S
Molecular Weight:195.2

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32315-10-9 Synthesis

32315-10-9
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6-Benzothiazolecarboxylicacid,2,3-dihydro-2-oxo-(9CI)

99615-68-6
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$288.00/500mg

Yield:99615-68-6 95%

Reaction Conditions:

Stage #1: 4-amino-3-mercaptobenzoic acidwith potassium carbonate in tetrahydrofuran at 20; for 0.5 h;
Stage #2: bis(trichloromethyl) carbonate in tetrahydrofuran at -78; for 1 h;

Steps:

68

(Intermediate Example 68) 2-Oxo-2,3-dihydrobenzothiazole-6-carboxylic acid 4-Amino-3-mercaptobenzoic acid (680 mg) was dissolved in tetrahydrofuran (20 ml), and potassium carbonate (550 mg) was added thereto and stirred for 30 minutes at room temperature. The mixture was cooled to -78°C, and triphosgene (400 mg) was added thereto and stirred for 1 hour. The mixture was warmed to roomtemperature and concentrated under reducedpressure until the volume of the solvent became 1/3. Water (20 ml) and formic acid were added to the concentrate until it became acidic, and precipitated crystals were collected by filtration and washed with water and n-hexane. The crystals were dried under reduced pressure to give the title compound (740 mg, Y.: 95%) as white crystals. ¹H NMR; (DMSO-d₆) δ (ppm): 6.3 (1H, brs), 7.1 (1H, d), 7.8 (1H, d), 8.1 (1H, s). ESI/MS (m/z): 194 (M-H)^-.

References:

EP1595866,2005,A1 Location in patent:Page/Page column 26

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