Abstract: The present invention relates to a process for the selective alkylation of intermediates of betaxolol.

Abstract: The present invention relates to a process for the selective alkylation of intermediates of betaxolol.

Abstract: Provided is a novel process for the preparation of iohexol having improved yields and purity, reduced number of isolated intermediates, and significantly reduced volume of ion-exchange resins required to desalinate the final product.

Abstract: The present invention provides a process for the preparation of BPD 1,4-diene diester A-ring comprising reacting hematoporphyrin IX dimethyl ester with dimethyl acetylenedicarboxylate followed by purification of the product by a series of fractional crystallizations.

Abstract: A process for the preparation of 2-chloro-4,5-difluorobenzoic acid and 2,4,5-trifluorobenzoic acid as well as synthetic intermediates useful in and prepared according thereto, comprising reacting a nitrobenzene having the formula ##STR1## wherein X is chloro or fluoro, with an appropriate carbanion to form a compound having the formula ##STR2## wherein one of Y and Z is chloro and the other is nitro, and R is a radical selected from the group consisting of --CCl.sub.3, --CH.sub.2 NO.sub.2, --CH(NO.sub.2)R.sup.1, --CH(CO.sub.2 R.sup.1).sub.2, --CH(C(O)R.sup.2).sub.2, --CH(CN)CO.sub.2 R.sup.1, --CH(CO.sub.2 R.sup.1)COR.sup.2 and --COR.sup.2 where R.sup.1 is alkyl or arylalkyl and R.sup.2 is alkyl, aryl or arylalkyl and, where appearing more than once in such a radical, R.sup.1 and R.sup.2 may be the same or different at each occurrence.

Abstract: A process for the preparation of 2-chloro-4,5-difluorobenzoic acid and 2,4,5-trifluorobenzoic acid as well as synthetic intermediates useful in and prepared according thereto, comprising reacting a nitrobenzene having the formula ##STR1## wherein X is chloro or fluoro, with an appropriate carbanion to form a compound having the formula ##STR2## wherein one of Y and Z is chloro and the other is nitro, and R is a radical selected from the group consisting of --CCl.sub.3, --CH.sub.2 NO.sub.2, --CH(NO.sub.2)R.sup.1, --CH(CO.sub.2 R.sup.1).sub.2, --CH(C(O)R.sup.2).sub.2, --CH(CN)CO.sub.2 R.sup.1, --CH(CO.sub.2 R.sup.1)COR.sup.2 and --COR.sup.2 where R.sup.1 is alkyl or arylalkyl and R.sup.2 is alkyl, aryl or arylalkyl and, where appearing more than once in such a radical, R.sup.1 and R.sup.2 may be the same or different at each occurrence.

Abstract: A process for the preparation of 2-chloro-4,5-difluorobenzoic acid and 2,4,5-trifluorobenzoic acid as well as synthetic intermediates useful in and prepared according thereto, comprising reacting a nitrobenzene having the formula ##STR1## wherein X is chloro or fluoro, with an appropriate carbanion to form a compound having the formula ##STR2## wherein one of Y and Z is chloro and the other is nitro, and R is a radical selected from the group consisting of --CCl.sub.3, --CH.sub.2 NO.sub.2, --CH(NO.sub.2)R.sup.1, --CH(CO.sub.2 R.sup.1).sub.2, --CH(C(O)R.sup.2).sub.2, --CH(CN)CO.sub.2 R.sup.1, --CH(CO.sub.2 R.sup.1)COR.sup.2 and --COR.sup.2 where R.sup.1 is alkyl or arylalkyl and R.sup.2 is alkyl, aryl or arylalkyl and, where appearing more than once in such a radical, R.sup.1 and R.sup.2 may be the same or different at each occurrence.

Abstract: A process for the preparation of halobenzoic acids, comprising the step of reacting a halonitrobenzene with a pyridinium salt to form an intermediate of the formula ##STR1## wherein R is selected from the group consisting of hydrogen, alkyl, aryl, alkenyl, alkynyl, --CN, --COOR' and --COR' where R' is alkyl or aryl; X is chloro or fluoro; Y is hydrogen, chloro or fluoro; and Z is chloro, bromo or iodo.