Abstract: There is disclosed a process for producing hexahydro-2-oxo-1H-thieno[3,4-d]imidazole-4-pentanoic acid of the formula (2): which is characterized by contacting a compound of the formula (1): wherein R1 and R2 represent a hydrogen atom or a benzyl group, but R1 and R2do not simultaneously represent a hydrogen atom, and R3 represents a hydrogen atom or a carboxyl group, with sulfuric acid in the presence of an aromatic hydrocarbon.

Abstract: A method for purifying O,S-dimethyl N-acetyphosphoramidothioate, which is characterized by subjecting a crude crystal of O,S-dimethyl N-acetylphosphoramidothioate to recrystallization by using a two-phase solvent system comprising water and an organic which is an aromatic hydrocarbon, an aliphatic carboxylic acid ester or aliphatic ketone, wherein the amount of water is 0.1 to 2 parts by weight and the amount of the organic solvent is 1 to 20 parts by weight to 1 part by weight of the crude O,S-dimethyl N-acetylphosphoramidothioate.

Abstract: A process is disclosed to produce an .alpha.-hydroxyiminophenylacetonitrile of the general formula [II]: ##STR1## wherein R.sup.1, R.sup.2, R.sup.3 and Z are each as defined in the specification, characterized in that a crude nitrile containing a phenylacetonitrile of the general formula [I]: ##STR2## wherein R.sup.1, R.sup.2, R.sup.3 and Z are each as defined in the specification, is reacted with an alkyl nitrite in the presence of a base, after which the reaction mixture is extracted with water and then the separated aqueous layer is neutralized with an acid. According to this production process, the desired .alpha.-hydroxyiminophenylacetonitrile can be produced with high purity, in high yield and with ease by extracting the reaction mass with water and then neutralizing the separated aqueous layer with an acid.

Abstract: A method for purifying O,S-dimethyl N-acetyphosphoramidothioate, which is characterized by subjecting a crude crystal of O,S-dimethyl N-acetylphosphoramidothioate to recrystallization by using a two-phase solvent system comprising water and an organic which is an aromatic hydrocarbon, an aliphatic carboxylic acid ester or aliphatic ketone, wherein the amount of water is 0.1 to 2 parts by weight and the amount of the organic solvent is 1 to 20 parts by weight to 1 part by weight of the crude O,S-dimethyl N-acetylphosphoramidothioate.

Abstract: A process is disclosed to produce a carboxylic acid derivative of the general formula VIII!: ##STR1## wherein R.sup.1, R.sup.2, R.sup.3 and L are each as defined in the specification, characterized in that a benzyl halide is reacted with a cyano compound to give a phenylacetonitrile, which is then reacted with an alkyl nitrite in the presence of a base to give an .alpha.-hydroxyiminophenylacetonitrile, which is then reacted with an alkylating agent to give an .alpha.-alkoxyiminophenylacetonitrile, which is then hydrolyzed in the presence of a base, or is hydrated and treated with an acid, followed by hydrolysis in the presence of a base, to give an .alpha.-alkoxyiminophenylacetic acid, which is then reacted with an acid halide forming agent, or is convened into a metal salt, followed by reaction with an alkylating agent, or is reacted with a lower alcohol in the presence of an acid catalyst.

Abstract: There is disclosed a process of producing an N-alkylacetamide of the general formula (III): ##STR1## wherein X.sup.1, X.sup.2 and X.sup.3 are the same or different and are independently hydrogen, lower alkyl, lower alkoxy, lower alkenyl, halogen or trifluoromethyl; R.sup.1 and R.sup.2 are the same or different and are independently lower alkyl; and represents a chemical bond of E- or Z-configuration, or a mixture of these configurations, which includes the steps of:(a) reacting an acetonitrile of the general formula (I): ##STR2## wherein X.sup.1, X.sup.2, X.sup.3, R.sup.1 and are each as defined above, with an alkylamine of the general formula (IV):R.sup.2 --NH.sub.2 (IV)wherein R.sup.2 is as defined above, to give an N-alkylacetamidine of the general formula (II): ##STR3## wherein X.sup.1, X.sup.2, X.sup.3, R.sup.1, R.sup.2 and are each as defined above; and(b) reacting the N-alkylacetamidine (II) with a nitrite derivative in the presence of an acid.