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AssigneeTeijin Limited
InventorsHiroshi Saitoh, Tsuyoshi Mizuno, Naoki Tsuchiya
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The present invention is a method of producing a 3-hydroxymethyl-benzo[b]thiophene derivative without the possible concomitant formation of isomers, which comprises selectively cyclizing a sulfoxide having X shown in the reaction scheme below: 1 wherein R1 to R3 are, same or independently, a hydrogen atom, an alkyl group having 1 to 4 carbons, a trihalomethyl group, an alkoxy group having 1 to 4 carbons, an alkylthio group having 1 to 4 carbons, or a trihalomethoxy group; R4 is an acyl group; X is a halogen atom, a hydroxy group, an amino group, a mercapto group, an alkylthio group having 1 to 9 carbons, an acyloxy group having 1 to 9 carbons, an acylamino group having 1 to 9 carbons, or a trihalomethoxy group.
A method of producing a 3-hydroxymethyl-benzo[b]thiophene derivative represented by the formula (II):
A method of producing a 3-hydroxymethyl-benzo[b]thiophene derivative represented by the above formula (II), wherein a benzo[b]thiophene derivative represented by the above formula (I) is produced by reducing a compound represented by the formula (IV):
A 3-hydroxymethyl-benzo[b]thiophene derivative represented by the formula (II):
A method of producing a 3-hydroxymethyl-benzo[b]thiophene derivative represented by the formula (I):
A 3-hydroxymethyl-benzo[b]thiophene derivative represented by the formula (I):
A method of producing a 3-hydroxymethyl-benzo[b]thiophene derivative represented by the formula (IV):
A benzo[b]thiophene derivative represented by the formula (IV):
Dependencies are inferred from the claim text.
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With only hydrogen atoms, hydrocarbon or substituted hydrocarbon radicals, directly attached to carbon atoms of the hetero ring: radicals…
Heterocyclic compounds
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The present invention relates to 3-hydroxymethyl-benzo[b]thiophene derivatives which are important as starting materials for the production of compounds useful in the pharmaceutical field, and methods for producing them.
3-Hydroxymethyl-benzo[b]thiophene derivatives represented by the formula (II): 2
wherein, R1 to R3 are, same or independently, a hydrogen atom, an alkyl group having 1 to 4 carbons, a trihalomethyl group, an alkoxy group having 1 to 4 carbons, an alkylthio group having 1 to 4 carbons, or a trihalomethoxy group, are very important as intermediates for the production of pharmacologically active compounds.
The examples of the present invention will now be explained below, but it should be noted that the present invention is not limited by these examples.
4-Bromo-3-nitrotoluene (60.35 g, 279 mmol), 5% by weight platinum carbon (1.09 g, 0.28 mmol) and triethylamine (112.93 g, 1116 mmol) were stirred under heating at 100° C., to which formic acid (99%) (42.39 g, 921 mmol) was added dropwise over 20 minutes. After stirring for 12 hours, it was brought back to room temperature, and then 100 ml of ethyl acetate and 100 ml of water were added thereto. After stirring well, it was filtered through celite to remove platinum carbon. By further adding 200 ml of ethyl acetate and 100 ml of water, it was extracted, the organic phase was washed with water (300 ml×3 times), and dried on magnesium sulfate. The solvent was evaporated to obtain 2-bromo-5-methylaniline (51.30 g, 276 mmol). The yield was 99%.
1H-NMR (270 MHz, CDCl3) δ(ppm): 7.260 (1H, d), 6.583 (1h<d), 6.439 (1H, dq), 3.991 (2H, s), 2.221 (3H, s)