Process for synthesizing substituted 2-benzo [b]thiophenecarboxylic acids and salts thereof
AssigneesUniroyal Chemical Company, Inc., Uniroyal Chemical Co./CIE.
InventorWalter Gerhard Brouwer
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Abstract
A process for the preparation of a substituted 2-benzo[b]thiophenecarboxylic acid compound or an alkali metal salt thereof, which comprises reacting a halobenzoyl derivative with mercaptoacetic acid in the presence of an alkali metal hydroxide and water. Substituted 2-benzo[b]thiophenecarboxylic acid compounds and alkali metal salts thereof are useful as intermediates for pharmaceuticals, agricultural chemicals, material preservatives, and the like.
Claims23
A process for the preparation of a 2-benzo-[b]thiophenecarboxylic acid compound of the formula ##STR8## wherein, R.sup.1 is H or C.sub.1 -C.sub.4 alkyl;
- and
- R.sup.2, R.sup.3, R.sup.4 and R.sup.5 are, independently, hydrogen, chlorine, fluorine, C.sub.1 -C.sub.4 alkyl, C.sub.1 -C.sub.4 alkoxy, C.sub.1 -C.sub.4 alkylthio, trifluoromethyl, acetyl, benzoyl, cyano or aryl,
- which process comprises
- (a) reacting a halobenzoyl compound of the formula ##STR9## wherein X is halogen, and R.sup.1, R.sup.2, R.sup.3, R.sup.4 and R.sup.5 are as described above,
- with mercaptoacetic acid in the presence of an alkali metal hydroxide and water, at a temperature of between about 100.degree. C. and 150.degree. C., and at a pressure of between about 5 and 50 psi,
- to produce a 2-benzo[b]thiophenecarboxylic acid alkali metal salt;
- and
- (b) neutralizing the 2-benzo[b]thiophenecarboxylic acid alkali metal salt, to produce the 2-benzo[b]thiophenecarboxylic acid compound.
A process for the preparation of a 2-benzo-[b]thiophenecarboxylic acid alkali metal salt of the formula ##STR10## wherein, R.sup.1 is H or C.sub.1 -C.sub.4 alkyl;
- R.sup.2, R.sup.3, R.sup.4 and R.sup.5 are, independently, hydrogen, chlorine, fluorine, C.sub.1 -C.sub.4 alkyl, C.sub.1 -C.sub.4 alkoxy, C.sub.1 -C.sub.4 alkylthio, trifluoromethyl, acetyl, benzoyl, cyano or aryl;
- and
- M is an alkali metal,
- which process comprises
- (a) reacting a halobenzoyl compound of the formula ##STR11## wherein X is halogen, and R.sup.1, R.sup.2, R.sup.3, R.sup.4 and R.sup.5 arc as described above,
- with mercaptoacetic acid in the presence of an alkali metal hydroxide and water, at a temperature of between about 100.degree. C. and 150.degree. C., and at a pressure of between about 5 and 50 psi,
- to produce the 2-benzo[b]thiophenecarboxylic acid alkali metal salt.
Dependencies are inferred from the claim text.