ChemicalBook CAS DataBase List Benzothiazole, 4-methyl- (7CI,8CI,9CI)

Benzothiazole, 4-methyl- (7CI,8CI,9CI) synthesis

6synthesis methods

Product Name:Benzothiazole, 4-methyl- (7CI,8CI,9CI)
CAS Number:3048-48-4
Molecular formula:C8H7NS
Molecular Weight:149.21

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Yield: 72%

Reaction Conditions:

with Isovaleronitrile in 1,4-dioxane at 70; for 0.5 h;

Steps:

1.1 Step-1 (4-Methyl benzothiazole)
Step-1
(4-Methyl benzothiazole)
A solution of 2-amino-4-methylbenzothiazolee (24.5 g, 149 mmol) in 745 mL of 1,4-dioxane was treated with isoamylnitrile (40.0 mL, 300 mmol) at 20°C and stirred at 70°C for 0.5 hr.
After the nitrogen evolution had subsided, the mixture was stirred at the same temperature for 1.5 h and concentrated in vacuo.
The residue was submitted to silica gel column chromathography with hexane:Et₂O = 3:1 to 2:1 as eluate to afford 4-methylbenzothiazole as a yellowish oil. (16.0 g, 107 mmol, 72%) R_f=0.45 (toluene:Et₂O=10:1); ¹H NMR (400MHz, CDCl₃) δ 8.98 (1H, s), 7.79 (1H, d, J = 6.8 Hz), 7.33 (2H, m), 2.80 (3H, s).

References:

Choongwae Pharma Corporation;KAHN, Michael EP1957516, 2016, B1 Location in patent:Paragraph 0093; 0094; 0095