NOVELTY - Preparing (M1) substituted 1-(cyclopropylmethoxy)-2-(difluoromethoxy)benzene (IV) involves: activating 3-(cyclopropylmethoxy)-4-(difluoromethoxy)-benzoic acid (II) with an activating agent (A') selected from carbonyldiimidazole (CDI), 1,1'-carbonyl-di-(1,2,4-triazol) (CDT), 1,1'-carbonyl-bis-(2-methylimidazole), 1,1'-carbonyl-dipiperidin, N,N'-dicyclohexylcarbodiimide (DCC), N,N'-diisopropylcarbodiimide (DIC), or 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide (EDC), and/or with N-hydroxysuccinimide or N-hydroxyphthalimide in an adequate solvent; and optionally isolating the compound (IV).    USE - For preparing substituted 1-(cyclopropylmethoxy)-2-(difluoromethoxy)benzene which is useful as an intermediate in preparation of Roflumilast (claimed) which is used as antiallergic and antiasthmatic application.    ADVANTAGE - The method obtains Roflumilast at higher yield of greater than or equal to 80%; can be implemented industrially; use activated forms of acid other than acid chloride; and avoids the use of thionyl chloride which is toxic/corrosive agent. The use of bases in the method, alternative to sodium hydride or tert-butoxyalkyl, are much more advisable in a industrial process, where it is not necessary to use a high excess of 3,5-dichloropyridine-4-amine. The method saves cost and is environmental friendly; and provides safe and economic advantages over known state of prior art.    DETAILED DESCRIPTION - Preparing (M1) substituted 1-(cyclopropylmethoxy)-2-(difluoromethoxy)benzene of formula (IV) involves: activating 3-(cyclopropylmethoxy)-4-(difluoromethoxy)-benzoic acid of formula (II) with an activating agent (A') selected from (a) carbonyldiimidazole (CDI), (b) 1,1'-carbonyl-di-(1,2,4-triazol) (CDT), (c) 1,1'-carbonyl-bis-(2-methylimidazole), (d) 1,1'-carbonyl-dipiperidin, (e) N,N'-dicyclohexylcarbodiimide (DCC), (f) N,N'-diisopropylcarbodiimide (DIC), or (g) 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide (EDC), and/or with (h) N-hydroxysuccinimide or (i) N-hydroxyphthalimide in an adequate solvent; and optionally isolating the compound (IV).    L=1H-imidazol-1-yl, 1H-1,2,4-triazol-1-yl, 2-methyl-1H-imidazol-1-yl, piperidin-1-yl, N,N'-dicyclohexylcarbamimidoyloxy, N,N'-diisopropylcarbamimidoyloxy, N'-(3-(dimethylamino)propyl)-N-ethylcarbamimidoyloxy, 2,5-dioxopyrrolidin-1-yloxy, or 1,3-dioxoisoindolin-2-yloxy.    An INDEPENDENT CLAIM is included for preparation (M2) of Roflumilast (I) involving: activating the compound (II) with activating agent (A') in an adequate solvent, to give an activated compound (II), preferably the compound (IV); optionally isolating the compound (IV); and reacting the compound (IV) with 3,5-dichloropyridin-4-amine (III) in presence of an inorganic base selected from alkali hydroxides, alkali carbonates and alkali fluorides, in an adequate solvent, and optionally in presence of a drying agent.