Substituted phthalides
AssigneeThe Hilton-Davis Chemical Co.
InventorsPaul J. Schmidt, Nathan N. Crounse
Life of this patent
Estimating the term…
Loading patent…
AssigneeThe Hilton-Davis Chemical Co.
InventorsPaul J. Schmidt, Nathan N. Crounse
Estimating the term…
Process comprises the combination of the three steps of condensing 3-N(R).sub.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).sub.2 phthalide (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).sub.2 benzoic acid (III), and oxidizing said benzoic acid to produce 3-Y-3-Z-5-X-6-N(R).sub.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-R.sup.1 -3-R.sup.2 -2-R.sup.1 -phenyl, 1-R.sup.5 -2-R.sup.6 -5/6-R.sup.4 -3-indolyl, 9-R.sup.7 -3-carbazolyl, 9-julolidinyl, 3,4-dioxymethylenephenyl, 2-thienyl, 1-R.sup.8 -2-pyrrolyl, or 4-pyridinyl; and Z is 4-R.sup.1 -3-R.sup.2 -2-R.sup.1 -phenyl, 1-R.sup.5 -2-R.sup.6 -5/6-R.sup.4 -3-indolyl or 1-R.sup.8 -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).sub.2 phthalides (II) and 2-(.alpha.-Y-.alpha.-Z)methyl-4-X-5-N(R).sub.2 benzoic acids (III) also have utility as colorless precursor color formers in carbonless duplicating and thermal marking systems.
A 3-(2-R.sup.3' -4-R.sup.1' -phenyl)-3-(2-R.sup.3 -3-R.sup.2' -4-R.sup.1" -phenyl) 5-X-6-N(R).sub.2 phthalide of the formula ##STR19## wherein:
Dependencies are inferred from the claim text.