Hetero diels-alder adducts of pentacene as soluble precursors of pentacene

A Diels-Alder adduct of a polycyclic aromatic compound with a dienophile, wherein said polycyclic aromatic compound is a polyacene rapresented by the formula:

• wherein each R3, R4, R5 and R6 is independently selected from the group consisting of:
• hydrogen, alkyl of 1–12 carbon atoms, aryl, a group wherein R3 and R4 together form one or more fused benzo rings and a group wherein R5 and R6 together form one or more fused benzo rings;
• and wherein n is 2–6;
• and wherein said dienophile is presented by the formula:
• R1—X═Y—R2
• wherein each X and Y is independently selected from the group consisting of:
• N and CR7;
• wherein R1—X═ together form a group selected from the group consisting of:
• O, S, SO and SO2;
• and
• wherein each R1, R2 and R7 is independently selected from the group consisting of:
• hydrogen, alkyl of 1–12 carton atoms, aryl, aralkyl, alkoxycarbonyl, aryloxycarbonyl, acyl and a group R, wherein R is selected from the group consisting of:
• hydrogen, alkyl of 1–12 carbon atoms, alkoxy, acyl, aryl, aralkyl, chloroalkyl, fluoroalkyl and substituted aryl having substituent selected from the group consisting of:
• —F, —Cl, —Br, —NO2, —CO2R, —PO3H, —SO3H, trialkylsilyl and acyl:
• wherein said acyl is represented by the formula:
• R8CO— wherein R8 is selected from the group consisting of:
• hydrogen, alkyl of 1–12 carbon atoms, aryl, aralkyl and fluoroalkyl;
• with the proviso that at least one of X and Y is a hetero atom selected from the group consisting of:
• N, O and S;
• wherein said Diels-Alder adduct of said polycyclic aromatic compound with said dienophile is represented by the formula:
• wherein X, Y, R1, R2, R3, R4, R5 and R6 are as previously defined.

A process for preparing a Diels-Alder adduct of a polycyclic aromatic compound with a dienophile, said process comprising the step of

• contacting:
• (a) polyacene compound represented by the formula:
• wherein each R3, R4, R5 and R6 is independently selected from the group consisting of:
• hydrogen, alkyl of 1–12 carbon atoms, aryl, a group wherein R3and R4 together form one or more fused benzo rings and a group wherein R5 and R6 together form one or more fused benzo rings, wherein n is 2–6;
• and
• (b) dienophile represented by the formula:
• R1 —X═Y—R2
• wherein each X and Y is independently selected from the group consisting of N and CR7;
• wherein R1—X═together form a group selected from the group consisting of:
• O, S, SO and SO2;
• wherein each R1, R2 and R7 is independently selected from the group consisting of:
• hydrogen, alkyl of 1–12 carbon atoms, aryl, substituted aryl, aralkyl, alkoxycarbonyl, aryloxycarbonyl, acyl and a group R, wherein R is selected from the group consisting of:
• hydrogen, alkyl of 1–12 carbon atoms, alkoxy, acyl, aryl, aralkyl, chloroalkyl, fluoroalkyl and substituted aryl having a substituent selected from the group consisting of:
• —F, —Cl, —Br, —NO2, —CO2R, —PO3H, —SO3H, trialkylsilyl and acyl;
• wherein said acyl is represented by the formula:
• R8CO— wherein R8 is selected from the group consisting of:
• hydrogen, alkyl of 1–12 carbon atoms, aryl, aralkyl and fluoroalkyl;
• with the proviso that at least one of X and Y is a hetero atom selected from the group consisting of:
• N, O and S;
• wherein said contacting is carried out under reaction conditions sufficient to produce said Diels-Alder adduct.

A process for preparing a Diels-Alder adduct comprising the step of:

• contacting:
• (a) a polycyclic aromatic compound represented by the formula:
• wherein each R3, R4, R5 and R6 is independently selected from the group consisting of:
• hydrogen, alkyl of 1–12 carbon atoms, aryl, a group wherein R3and R4 together form one or more fused benzo rings and a group wherein R5 and R6 together form one or more fused benzo rings, wherein n is 2–6;
• and
• (b) dienophile selected from the group consisting of compounds represented by the formula:
• R—N═O, RCO—N═S═O, and RO—CO—N═N—COOR,
• wherein R is selected from the group consisting of:
• alkyl of 1–12 carbon atoms, aryl, aralkyl, chloroalkyl, fluoroalkyl and substituted aryl having a substituent selected from the group consisting of:
• —F, —Cl, —Br, —NO2, —CO2R, and trialkylsilyl;
• wherein said contacting is carried out under reaction conditions sufficient to produce said Diels-Alder adduct.