Processes for preparing dianthranilate compounds and diazopyridone colorants

A process for preparing dianthranilate compounds which comprises (a) admixing reactants as follows:

• (1) a diol of the formula R1(OH)2, wherein R1 is an alkylene group having about 36 carbon atoms, and wherein the —OH groups are primary or secondary, (2) isatoic anhydride, present in an amount of at least about 2.2 moles of isatoic anhydride per every one mole of diol and present in an amount of no more than about 2.5 moles of isatoic anhydride per every one mole of diol, (3) a catalyst which is 1,4-diazabicyclo[2.2.2]octane, said catalyst being present in an amount of at least about 0.25mole of catalyst per every one mole of diol, and (4) a toluene solvent, wherein the reactants are insoluble in the solvent, resulting in a heterogeneous reaction mixture, wherein the diol and the solvent are present in relative amounts of at least about 0.5 mole of diol per liter of solvent;
• (b) heating the mixture thus formed to a temperature of at least about 40° C. and to a temperature of no more than about 200° C. for a period of at least about 2.5 hours and for a period of no more than about 3.5 hours to form a dianthranilate compound of the formula
• (c) subsequent to formation of the dianthranilate compound, quenching excess isatoic anhydride by the addition of aqueous sodium hydroxide, aqueous potassium hydroxide, methanol, ethanol, or mixtures thereof;
• and (d) separating the dianthranilate compound from the mixture by liquid-liquid extraction.

A process for preparing a diazopyridone colorant which comprises (I) preparing a dianthranilate compound by (a) admixing (1) a diol of the formula R1(OH)2, wherein R1 is an alkylene group having at least about 20 carbon atoms, and wherein the —OH groups are primary or secondary, (2) isatoic anhydride, present in an amount of at least about 2 moles of isatoic anhydride per every one mole of diol, (3) a catalyst which is 1,4-diazabicyclo[2.2.2]octane, N,N,N′,N′-tetramethylethylene diamine, or a mixture thereof, said catalyst being present in an amount of at least about 0.2 mole of catalyst per every one mole of diol, and (4) a solvent;

• and (b) heating the mixture thus formed to form a dianthranilate compound of the formula
• (II) reacting the dianthranilate compound with nitrosylsulfuric acid to form a diazonium salt of the formula
• and (III) reacting the diazonium salt with a pyridone compound of the formula
• wherein R2 is (i) an alkyl group, (ii) an aryl group, (iii) an arylalkyl group, (iv) an alkylaryl group, (v) an alkoxy group, (vi) an aryloxy group, (vii) an arylalkyloxy group, (viii) an alkylaryloxy group, (ix) a polyalkyleneoxy group, (x) a polyaryleneoxy group, (xi) a polyarylalkyleneoxy group, (xii) a polyalkylaryleneoxy group, (xiii) a heterocyclic group, (xiv) a silyl group, (xv) a siloxane group, (xvi) a polysilylene group, (xvii) a polysiloxane group, or (xviii) a group of the formula
• wherein r and s are each, independently of the other, integers representing a number of repeat —CH2— groups, and R3 is (i) an alkyl group, (ii) an aryl group, (iii) an arylalkyl group, or (iv) an alkylaryl group, to form a diazopyridone compound of the formula