| 摘要 |
1321296 Substituted benzo-pyrans BEECHAM GROUP Ltd 9 Sept 1971 [10 Sept 1970 11 May 1971] 43347/70 and 14225/71 Heading C2C Novel compounds of Formula II and their salts where R 1 is a hydrocarbon group of 1 to 6 carbon atoms, R 2 is a 5-membered heteroaromatic, R 3 is a hydroxy group (or a salt or etherified or esterified derivitive) and R 4 is a saturated or unsaturated alkyl group of 1 to 20 carbon atoms or a C 3 -C 8 cyclo alkyl- C 1 -C 6 alkyl group and compounds of Formula II in which R 2 may also be a six-membered hetero-aromatic and R 3 and R 4 may be one of hydrogen, hydroxy (or a derivative thereof) or a non-aromatic hydrocarbon group of 1 to 20 carbon atoms are prepared by reacting a chromanone of general Formula III with a metallic compound of general formula R 2 X where X is an alkali metal (preferably lithium) or a magnesium halogen group in the presence of a proton source to give a compound of general Formula (IV) and allowing or causing the dehydration of this compound to give a compound of general Formula (II). Intermediate compounds of general Formula (IV) may be isolated before dehydration which may be carried out by heating or use of an acid catalyst. Compounds of general Formula (II) are central nervous system depressants and form, with a carrier, diluent or excipient, a pharmaceutical preparation which may be administered orally or parenterally. |
