Synthesis of thiophenes and thiapyrans. III. Hydroxythianaphthenes and alkoxythianaphthenes was written by Sunthankar, A. V.;Tilak, B. D.. And the article was included in Proceedings – Indian Academy of Sciences, Section A in 1951.Formula: C9H8OS This article mentions the following:
Monomethoxythianaphthalenes are prepared by condensing a mercaptoanisole with BrCH2CH(OMe)2 (I) and effecting a ring closure of the resulting sulfide. p-MeOC6H4SH (7.6 g.), 1.2 g. Na, 1.25 g. NaI, 9.3 g. I, and 25 cc. absolute alc. boiled 2 h., and the crude product distilled yields 70% p-methoxyphenyl 2,2-dimethoxyethyl sulfide (II), b2.5-3 155-60°; dinitrophenylhydrazone, m. 106-7°. From 6.1 g. II added to 30 g. P2O5 and 10 cc. H3PO4 at 150-60°/0.34 mm. is obtained 5-methoxythianaphthene (isolated as the picrate), which after distillation forms a white solid, m. 42-3°, b0.52 85-90°; the yield is poor. Similarly prepared were m-methoxyphenyl 2,2-dimethoxyethyl sulfide, b2.5 125-30° (2,4-dinitrophenylhydrazone, m. 123-4°); 6-methoxythianaphthene, b16 153-6° (62% yield)(picrate, m. 105-6°); o-methoxyphenyl 2,2-dimethoxyethyl sulfide, b15 175-80° (2,4-dinitrophenylhydrazone, m. 135-6°); 7-methoxythianaphthene, (III), b15 140-5° (yield 18%)(picrate, m. 110-11°); p-ethoxyphenyl 2,2-dimethoxyethyl sulfide, b12 180° (2,4-dinitrophenylhydrazone, m. 84-5°); 5-ethoxythianaphthene, b12 145° (picrate, m. 93°); 3-methoxy-p-toluenethiol, b12 130°; 3-methoxy-4-methylphenyl 2,2-dimethoxyethyl sulfide, b15 185° (2,4-dinitrophenylhydrazone, m. 123-4°); 6-methoxy-5-methylthianaphthene (IV), m. 62-3°, b12 160° (picrate, m. 107-8°); 6-methoxy-5-methylthianaphthene 1,1-dioxide (from 0.45 g. IV, 7 cc. glacial AcOH, and 3 cc. H2O2 heated 6 h. at 85°), m. 187°. Demethylation of 0.62 g. III with 5 g. pyridine-HCl by heating 9 h. at 180° gave 0.5 g. (88%) 7-hydroxythianaphthene, b8 135°, m. 67-8° (picrate, m. 184-6°); from IV by the same procedure is obtained 6-hydroxy-5-methylthianaphthene, m. 146-7°, b10 160-5°. All b.ps. are given as bath temperature In the experiment, the researchers used many compounds, for example, 6-Methoxybenzo[b]thiophene (cas: 90560-10-4Formula: C9H8OS).
6-Methoxybenzo[b]thiophene (cas: 90560-10-4) belongs to benzothiophene derivatives. Benzothiophenes are valuable heterocycles that are widely used in medicines, agrochemicals, and materials science. Its aromaticity makes it relatively stable, although as a heterocycle, it has reactive sites which allow for functionalization.Formula: C9H8OS
Referemce:
Benzothiophene – Wikipedia,
Benzothiophene | C8H6S – PubChem