| abstract |
ABSTRACT OF THE DISCLOSURE Process comprises the combination of the three steps of condemsing 3-N(R)2-4-X-benzoic acid with an aromatic or hetero-cyclic aldehyde, YiCHO, under acidic conditions to produce 3-Y-5-X-6-N(R)2phthalide (II), condensing said phthalide with a compound of the formula Z-H under alkaline or acid conditions to produce 2-(.alpha.-Y-.alpha.-Z)methyl-4-X-5-N(R)2benzoic acid (III), and oxidizing said benzoic acid to produce 3-Y-3-Z-5-X-6-N(R)2phthalide (I) where: R is hydrogen, non-tertiary alkyl of one to four carbon atoms, benzyl or substituted benzyl; X is hydrogen or halo; Y is 4-R1-3-R2-2-R1-phenyl, 1-R5-2-R6-5/6-R4-3-indolyl, 9-R7-3-carbazolyl, 9-julolidinyl, 3,4-dioxymethylenephenyl, 2-thienyl, 1-R8-2-pyrrolyl, or 4-pyridinyl; and Z is 4-R1-3-R2-2-R1-phenyl, 1-R5-2-R6-5/6-R4-3-indolyl or 1-R8-2-pyrrolyl which are useful as colorless precursor color formers in carbonless duplicating and in thermal marking systems. The intermediates, 3-Y-5-X-6-N(R)2-phthalides (II) and 2-(.alpha.-Y-.alpha.-Z)methyl-4-X-5-N(R)2benzoic acids (III) also have utility as colorless precursor color formers in carbonless duplicating and thermal marking systems. |