Abstract: A process for producing DL-phenylalanine by reacting an .alpha.-halogeno-.beta.-phenylpropionic acid represented by the general formula: ##STR1## where X is a halogen atom, or its salt, with ammonia, characterized in that the reaction is conducted while supplying the .alpha.-halogeno-.beta.-phenylpropionic acid or its salt into aqueous ammonia charged in a reactor in advance.

Abstract: A process for producing an .alpha.-halogeno-.beta.-phenylpropionic acid represented by the general formula: ##STR1## where X is a halogen atom, which comprises hydrolyzing under heating a halogen-containing ethylbenzene derivative represented by the general formula: ##STR2## where W is a cyano group, an amidocarbonyl group or a lower alkoxycarbonyl group, and X is as defined above, in an aqueous mineral acid solution under vigorous stirring.

Abstract: .alpha.-L-aspartylphenylalanine lower alkyl esters are prepared by a process wherein fumaric acid, ammonia and a lower alkyl ester of L-phenylalanine are contacted with a culture or treated culture of a microorganism belonging to the genus Pseudomonas, and being capable of producing a .alpha.-L-aspartyl-L-phenylalanine lower alkyl ester from fumaric acid, ammonia and a lower alkyl ester of L-phenylalanine.

Abstract: A process for producing a halogen-containing ethylbenzene derivative represented by the general formula: ##STR1## where X is a halogen atom, and Y is a nitrile group, a carboxyl group, a lower alkoxycarbonyl group or an amidocarbonyl group, which comprises reacting a vinyl compound represented by the general formula:CH.sub.2 .dbd.CH--Y (II)where Y is as defined above, with a benzenediazonium salt and halogen ions in a solvent mixture comprising a lower alcohol and/or an ether, and water, under an acidic condition with a mineral acid, in the presence of a monovalent copper compound as a catalyst.

Abstract: A process for producing a halogen-containing ethylbenzene derivative represented by the general formula: ##STR1## where X is a halogen atom, and W is a nitrile group, a carboxyl group, a lower alkoxycarbonyl group or an amidocarbonyl group, which comprises diazotizing aniline with a nitrite in a solution mixture comprising a hydrophilic organic solvent, an aqueous mineral acid solution and a vinyl compound represented by the general formula:CH.sub.2 .dbd.CH--W (II)where W is as defined above, to form a benzenediazonium salt, and reacting the benzenediazonium salt, without isolating it from the reaction system, with said vinyl compound in the presence of halogen ions and a copper compound as a catalyst.