| 摘要 |
1,271,872. Preparation of hydroquinones; Vitamin K. TAKEDA YAKUHIN KOGYO K.K. 16 May, 1969 [20 May, 1968], No. 24982/69. Headings C2C and C2V. Compounds of Formula I: in which each of R<SP>1</SP> and R<SP>2</SP> is OCH 3 or CH 3 , or R<SP>1</SP> and R<SP>2</SP> together represent and R is a radical where X and Y are H or together represent a second bond and n is 0 or 1-9, are prepared by condensing compounds II: with alcohols of the formulµ or in the presence of an N-sulphinyl compound as condensing agent. In the examples the hydroquinones are not isolated, but are oxidized immediately to the corresponding quinones. Amongst others the examples describe the preparation of the vitamin-2 - methyl - 3 - phytyl - 1,4 - naphthoquinone.
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