Patent GB-324661-A (GB)
Title: A process for the manufacture and production of derivatives of naphthalene
Filed: 1928-09-26
Abstract: 324,661. Johnson, J. Y., (I. G. Farbenindustrie Akt.-Ges.). Sept. 26, 1928. Naphthalene derivatives are obtained by condensing benzoquinone itself, or benzoquinones substituted in the 2- or in the 2- and 3-positions, with 1 : 3-butadienes, If benzoquinone itself is used, mild conditions are employed, such as low temperatures and short duration of the reaction, or the use of the butadiene in less than two molecular proportions to each molecular proportion of the benzoquinone, in order to avoid the formation of anthracene derivatives. The condensation products first formed undergo hydrogen displacement when heated alone or in the presence of a diluent, or when treated with acid or alkaline agents; the hydrogenated 1 : 4-dioxynaphthalenes thus obtained can be converted into naphthoquinones by dehydrogenation; intermediate products including bodies of a quinhydronic character and hydrogenated naphthoquinones being obtained under mild conditions. In examples, (1) benzoquinone is condensed with 1 :3-butadiene, isoprene, and 2 : 3-dimethyl-1 : 3-butadiene, (2) Toluquinone is condensed with 1 : 3-butadiene, (3) monochlorbenzoquinone is condensed with 2 : 3-dimethyl-1 : 3-butadiene, (4) 2 : 3-dichlorbenzoquinone is condensed with 1:3-butadiene and 2 : 3-dimethyl-1 : 3-bubadiene, (5) the condensation product from benzoquinone and 1 : 3- butadiene is dissolved in alcohol and water and warmed with hydrochloric acid, 5 : 8-dihydro-1 : 4-dioxynaphthalene is obtained; the same product is obtained by heating the parent material above its melting-point, or by warming it with caustic soda solution, (6) 5 : 8-dihydro-1 : 4-dioxynaphthalene is oxidized with ferric chloride in glacial acetic acid ; 5 :8-dehydro-1 : 4-naphthoquinone or an intermediate product of quinhydronic nature is obtained according to the conditions, or the same products may be obtained directly from the condensation product of benzoquinone and 1 : 3- butadiene, (7) 5 : 8-dihydro-1 : 4-dioxynaphthalene is oxidized with potassium bichromate, 1 : 4- naphthoquinone is obtained, (8) the condensation product from benzoquinone and 2 :3-dimethyl- 1 : 3-butadiene is converted into 5 : 8-dihydro- 6: 7-dimethyl-1 :4-dioxynaphthalene by heating with hydrochloric acid; the product is oxidized with potassium bichromate, yielding 5 : 8-dihydro-6 : 7-dimethyl-1 : 4-naphthoquinone and 6 : 7-dimethyl-1 : 4-naphthoquinone according to the conditions, (9) the condensation product from toluquinone and 1: 3-butadiene is converted into 2-methyl-5 : 8-dihydro-1 : 4-dioxynaphthalene by treatment with hydrochloric acid, the product, on oxidation with potassium bichromate, yields 2-methyl-1 : 4 naphthoquinone, (10) the condensation product from benzoquinone and isoprene is similarly converted into 6-methyl-5 : 8-dihydro- 1 : 4-dioxynaphthalene; the product, on oxidation, yields 6-methyl-1 : 4-naphthoquinone, (11) the condensation product from 2 : 3-dichlorbenzoquinone and 2 : 3-dimethyl-1 : 3-butadiene is oxidized with potassium bichromate to yield 6 : 7-dimethyl-2 : 3-dichlor-1 : 4-naphthoquinone.