Patent ID: 6252092
Filing Date: 2001-06-26
Classification: C07D

Abstract:
Process for the synthesis of 5-alkylbenzo[1,3]dioxoles comprising the following steps:(a) catalytic hydrogenation of 4-acylphenol of formula (I), where R.sub.1 is a C.sub.1 -C.sub.17 alkyl, to give 4-alkylphenol of formula (II) ##STR1##(b) acylation of compound (II) with an acyl group containing up to 3 carbon atoms, to give a compound of formula (III), where R.sub.3 is methyl or ethyl ##STR2##(c) reacting compound (III) with a Lew is acid to give 4-alkyl-2-acylphenol (IV) ##STR3##(d) reacting compound (IV) at 0.degree. C. to 25.degree. C. with hydrogen peroxide and a hydroalcoholic solution containing an inorganic basic compound, wherein the basic compound/compound (IV) molar ratio equal to 0.8:1 to 2:1 to give 4-alkylcatechol (V) ##STR4##(e) cyclization of compound (V) with a compound of formula X--CH(R.sub.2)--Y, where X and Y, identical or different, may be each selected: (i) from the group consisting of chlorine, bromine, iodine, or (ii) from the group consisting of CH.sub.3 O--, C.sub.2 H.sub.5 O--, and where R.sub.2 is H, or a C.sub.1 -C.sub.3 alkyl, to give 5-alkylbenzo[1,3]dioxole (VI) ##STR5##