Method for asymmetric synthesis of derivatives of 1,4-dihydro-2H-3,1-benzoxazin-2-one, method for the manufacture of intermediate compounds and (S)-6-chloro-4-(cyclopropylethynyl)-1,4-dihydro-4-(trifluormethyl)-2-(4'methoxyphenyl)-3,1-benzoxazine

摘要

Process for asymmetric synthesis of benzoxazinone derivatives of formula (VI), comprises: (a) reacting (I) with (VII) or (VIII) in the presence of an acid catalyst to give (II) which is reacted with a mixture of (IX), alkyl lithium and cyclopropylacetylene to give (III); (b) (III) is oxidised to (IV) and this is reacted with a cleaving agent and a trapping agent to give (V); and (c) (V) is treated with a cyclising agent to give (VI). X = Cl or F; A = CF3, C2F5 or C3F7; R1 = H, 1-6C alkyl or 1-6C alkylcarbonyl; R2 = H; R3 = H, Me, Et or phenyl substituted by up to 3 of R12; R4, R5, R4a, R5a, R6, R8, R9 = H, 1-6C alkyl, 1-6C alkoxy or 1-6C alkylthio; R12 = H, 1-6C alkyl, 1-6C alkoxy or 1-6C alkylthio; Y = (CH2)n or O; n = 0 to 3; P = amine protecting group of formula (a) or (b); P" = group of formulae (c) or (d); R10, R11 = 1-4C alkyl; or NR10R11 = pyrrolidinyl, piperidinyl or morpholinyl.