Abstract: The invention relates to a process improvement for making [R-(R*,R*)]-5-[2-[5-(3-chlorophenyl)-2-oxo-3-oxazolidinyl]propyl]-1,3-benz odioxole-2,2-dicarboxylic acid dimethyl ester an intermediate used in the synthesis of beta-3 agonist, [R-(R*,R*)]-5-[2-[5-(3-chlorophenyl)-2-hydroxyethyl]amino]propyl]-1,3-benz odioxole-2,2-dicarboxylic acid disodium salt.

Abstract: The invention is a process improvement for producing [R-(R*, R*)]-5-(3-chlorophenyl)-3-[2-(3,4-dihydroxyphenyl)-1-methylethyl]-2-oxazol idinone which is an intermediate useful in making compounds that have antidiabetic and/or antihyperglycemic and/or antiobesity properties in mammals.

Abstract: A novel process for producing 5-[(substituted)amino]-8-[phenyl or substituted-phenyl]-3H,6H-1,4,5a,8a-tetraazaace-naphthylen-3-ones of the formula: ##STR1## Where R.sub.1, R.sub.2 and R.sub.3 are defined in the specification by reacting a 4,5-dihydro-7-[phenyl or substituted phenyl]pyrazolo[1,5-a]pyrimidine-3-carboxamide with carbon disulfide and a suitable base and a lower alkyl iodide to give a 5-(lower alkylthio)-8-[phenyl or substituted phenyl]-3H,6H-1,4,5a,8a-tetraazaacenaphthylen-3-one which is further reacted with an amine of the formula: ##STR2## to give the desired compounds is disclosed as well as 5-(loweralkylthio)-8-phenyl-3H,6H,1,4,5a,8a-tetra azaacenaphthylen-3-ones useful as intermediates in the process.