7085-93-0Relevant academic research and scientific papers
3-(substituted phenyl)phthalides
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, (2008/06/13)
Process comprises the combination of the three steps of condensing 3-N(R)2 -4-X-benzoic acid with an aromatic or heterocyclic aldehyde, Y-CHO, under acidic conditions to produce 3-Y-5-X-6-N(R)2 phthalide (II), condensing said phthalide with a compound of the formula Z-H under alkaline or acid conditions to produce 2-(α-Y-α-Z)methyl-4-X-5-N(R)2 benzoic acid (III), and oxidizing said benzoic acid to produce 3-Y-3-Z-5-X-6-N(R)2 phthalide (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-(α-Y-α-Z)methyl-4-X-5-N(R)2 benzoic acids (III) also have utility as colorless precursor color formers in carbonless duplicating and thermal marking systems.
