Methyl 3,5-dimethoxy-4-methylbenzoate

Methyl di-O-methylorsellinate, Methyl 2,4-dimethoxy-6-methylbenzoate (Di-0-methylorsellinsauremethylester, 2,4-Dimethoxy-6-methylbenzoesauremethylester)... 

Nitropyrido[l,2-A]quinolin-6-ium-l 1-olate (6%) was isolated from a reaction mixture obtained by photoirradiation of crystalline photochromic 2-(2, 4 -dinitrobenzyl)pyridine for 10 days <2004JP0865>. Reaction of l-(3-chloropropyl)-6,7-dimethoxy-3-methylbenzo[c]pyrylium perchlorate with hydrazines and hydroxylamine in refluxing MeOH afforded 9,10-dimethoxy-6-methyl-, -4,6-dimethyl-l,2,3,4-tetrahydropyridazino[6,l-tf]isoquinoli-nium, and 9,10-dimethoxy-6-methyl-l,2,3,4-tetrahydro[l,2]oxazino[3,2- ]isoquinolinium, perchlorates, respectively <2004CHE1131>. 

The use of open-chain precursors for obtaining the benzenoid ring in anacardic and orsellinic acids has proved a fruitful approach. Ethyl 2-methoxy-6-methylbenzoate (synthesised through the Michael addition of ethyl acetoacetate virith but-2-en-al, followed by cyclisation and aromatisation), has been alkylated in an aprotic solvent after formation of the carbanion with lithium di-isopropylamide (refs. 113,114) to give the anacardic after hydrolysis and demethylation (a). In a similar way ethyl 2,4-dimethoxy-6-methylbenzoate (ethyl orsellinate), (formed from ethyl acetoacetate and ethyl crotonate followed by cyclisation aromatisation and methylation (ref. 115)), has been alkylated (ref. 116, 117). In this way the C.,5 orsellinic acid precursor [R = C14H29 in route (b)] of the component phenols in Anacardium occidentale has been synthesised (ref. 118) and the method indirectly affords another route to the cardol series. 

Hydroxy-3,8-dimethoxy-2-methylanthraquinone, in T-10161 1 -Hydroxy-5,6-dimethoxy-2-methylanthraquinone, in T-10160 7-Hydroxy-2,8-dimethoxy-1 -methyl-4-aza-9-fluorenone, in T-30198 7-Hydroxy-3,4-dimethoxy-5-methylbenzo[/z] quinolin-2(l/7)-one, see A-10131 7-Hydroxy-2,9-dimethoxy-4-methyl-6//-dibenzo[, f/]pyran-6-one, see S-10001... 

Crystals (EtOH-HjO), mp 157-158 °C Deriv Methyl 2,6-dimethoxy-3-chloro-4-meth-ylbenzoate, mp 71-72 °C, from 2,6-dimethoxy-3-chloro-4-methylbenzoic acid with CH2N2 Lit Roller and Popl 1934a... 

Di-0-methyl-3,5-diehloroorsellinic acid, 2,4-Dimethoxy-3,5-dichloro-6-methylbenzoic acid... 

Ethyl 2,4-di-0-methyl-3-chloroorsellinate5 Ethyl 2,4-dimethoxy-3-chloro-6-methylbenzoate (2,4-Di-0-methyl-3-chlororsellinsaureethylester, 2,4-Dimethoxy-3-chlor-6 methylbenzoesaureethylester)... 

Preparation by reduction of the 2, 6-dimethoxy-4,6 -dimethylspiro[81574-67-6]-3(2H),4 -dione (SM) with zinc dust in acetic acid for 1 h (83%). SM was obtained from methyl 4-methoxy-2-(2,4-dimethoxy-6-methyl-phenoxy)-6-methylbenzoate by treatment with titanium tetrachloride and hydrogen chloride for 40 h (65%, m.p. 190-192°) [1184]. 

Preparation by hydrogenolysis of 4,6, 6 -tris-(benzyloxy)-3,3 -dichloro-2, 4 -dimethoxy-2-methyl-benzophenone (SM) in ethyl acetate/tetrahydrofuran in the presence of 10% Pd/C at 25° (29%). SM was obtained by condensation of 4,6-bis(benzyloxy)-3-chloro-2-methylbenzoic acid with 4-chloro-3,5-dime-thoxyphenol benzyl ether in the presence of trifluoroacetic anhydride in methylene chloride under nitrogen for 20 min [1179]. m.p. 217-219° [1179] H NMR [1179], IR [1179], MS [1179]. 

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