NOVELTY - Preparing a tetrasubstituted pentacene compound (A) comprises: oxidizing 1,2-bis(hydroxymethyl)-3,6-dimethylbenzene (3a) to form 1-hydroxy-4,7-dimethy-1,3-dihydro-isobenzofuran (5a); methylating (5a) to form methoxy-isobenzofuran compound (5b); eliminating methoxy group in (5b) to form 4,7-dimethyl-isobenzofuran (6a); reacting (6a) with benzoquinone to form 1,4,8,11-tetramethyl-5,14,7,12-diepoxy-5,7,12,14-octahydropentacene-6,13-dione (7a); dehydrating (7a) to form 1,4,8,11-tetramethyl-6,13-pentacenequinone (8a); and alkylating (8a) with a metal acetylide to form a pentacene compound (9a).    USE - (A)/the formulation is useful as charge transport, semiconducting, electrically conducting, photoconducting or light emitting material or component in optical, electrooptical, electronic, electroluminescent or photoluminescent components or devices, which are electrooptical displays, LCDs, optical films, retarders, compensators, polarizers, beam splitters, reflective films, alignment layers, color filters, holographic elements, hot stamping foils, colored images, decorative or security markings, liquid crystal pigments, adhesives, non-linear optic devices, optical information storage devices, electronic devices, organic semiconductors, organic field effect transistors, integrated circuits, thin film transistors, radio frequency identification tags, organic light emitting diodes, organic light emitting transistors, electroluminescent displays, organic photovoltaic devices, organic solar cells, organic laser diodes, organic integrated circuits, lighting devices, sensor devices, electrode materials, photoconductors, photodetectors, electrophotographic recording devices, capacitors, charge injection layers, Schottky diodes, planarizing layers, antistatic films, conducting substrates, conducting patterns, photoconductors, electrophotographic applications, electrophotographic recording, organic memory devices, biosensors, biochips (all claimed), electrophotographic devices, and security markings to authenticate and prevent counterfeiting of documents of value e.g. banknotes, credit cards or identity (ID) cards, national ID documents, licenses and any product with monetary value (e.g. stamps, tickets, shares and cheques). (A) is useful as backlight of e.g. LCDs.    ADVANTAGE - (A) has improved solubility in standard organic solvents, charge carrier mobility and stability especially against air, heat and light. (A) provides improved semiconducting materials with good processibility.    DETAILED DESCRIPTION - Preparation of a 1,4,8,11-tetrasubstituted pentacene compound (A) comprises: (a1) reduction of 4,7-dimethyl-isobenzofuran-1,3-dione (2a) in the presence of a reducing agent to form 4,7-dimethyl-3H-isobenzofuran-1-one (4a), or (a2) oxidation of 1,2-bis(hydroxymethyl)-3,6-dimethylbenzene (3a) in the presence of an oxidizing agent to form (4a), or (a3) oxidation of (3a) in the presence of an oxidizing agent to form 1-hydroxy-4,7-dimethy-1,3-dihydro-isobenzofuran (5a); in case of step (a1) or step (a2), (b) reduction of (4a) in the presence a reducing agent to form (5a); (c) methylation of (5a) to form 1-methoxy-4,7-dimethy-1,3-dihydro-isobenzofuran (5b); (d) elimination of methoxy group in (5b) in the presence of a base to form 4,7-dimethyl-isobenzofuran (6a); (e) reaction of (6a) with p-benzoquinone by Diels-Alder cycloaddition to form 1,4,8,11-tetramethyl-5,14,7,12-diepoxy-5,7,12,14-octahydropentacene-6,13-dione (7a); (f) dehydration of (7a) in the presence of a base to form 1,4,8,11-tetramethyl-6,13-pentacenequinone (8a); and (g) alkylation of (8a) with a monosubstituted metal acetylide to form a 1,4,8,11-tetrasubstituted 6,13-bis(1-substituted ethynyl) pentacene compound of formula (9a).R = alkyl.    INDEPENDENT CLAIMS are included for:    (1) the 1,4,8,11-tetrasubstituted pentacene compound of formula (Aa) obtained by the process; and    (2) a formulation comprising (Aa), one or more organic binders or their precursors, and optionally one or more solvents.    X = SiR5R6R7 or Ar1;    R1-R7 = carbyl or hydrocarbyl; and    Ar1 = optionally substituted (hetero)aryl.