Patent ID: 8653259

Claim:
A process for preparing heterocycles of formula Ia, wherein: X is sulfur, oxygen or NR5, where R5 is hydrogen or (C1-C4)alkyl; n is zero, 1, 2 or 3; Ar is phenyl, naphthyl or heteroaryl, each of which may be optionally substituted by 1, 2, 3, 4 or 5 R11 radicals where R11 is in each case independently selected from the group consisting of (C1-C4)alkyl, F, Cl, Br, I, CN, NO 2 , OH, O(C1-C4)alkyl, and COO(C1-C4)alkyl, and some or all of the hydrogen atoms of the alkyl radicals may be replaced by fluorine atoms; R1, R2, R3 and R4 are each independently hydrogen, F or (C1-C4)alkyl where some or all of the hydrogen atoms of the alkyl radicals may be replaced by fluorine atoms; or R1 and R3 together are a bond, and R2 and R4, together with the two carbon atoms to which they are attached, form an aromatic six-membered carbocycle in which one or two carbon atoms may be replaced by nitrogen and the aromatic six-membered ring may be substituted by 1, 2, 3 or 4 R7 radicals, where R7 is in each case independently selected from the group consisting of (C1-C4)alkyl, F, Cl, Br, I, CN, NO 2 , OH, O(C1-C4)alkyl, and COO(C1-C4)alkyl, and some or all of the hydrogen atoms of the alkyl radicals may be replaced by fluorine atoms, where n=0; or R1 and R3 are each independently hydrogen or (C1-C4)alkyl and R2 and R4, together with the two carbon atoms to which they are attached, form a saturated 5-, 6-, 7- or 8-membered carbocycle in which one or two carbon atoms may be replaced by O, S, NH and N(C1-C4)alkyl and which carbocycle may be substituted by 1, 2, 3, 4, 5 or 6 R8 radicals where R8 is in each case independently selected from the group consisting of (C1-C4)alkyl, O(C1-C4)alkyl, and COO(C1-C4)alkyl, and some or all of the hydrogen atoms of the alkyl radicals may be replaced by fluorine atoms, where n=0; excluding compounds in which Ar is unsubstituted phenyl, X is oxygen or sulfur, R1 and R2 are each independently hydrogen, (C1-C4)alkyl or benzyl, R3 and R4 are each hydrogen and n is zero, and their tautomers and their salts, which process comprises, as shown in scheme 2 a) reacting an aromatic isothiocyanate of formula IIa with a primary amine of formula IIIa to give a thiourea of formula IVa, and b) converting the thiourea of formula Iva, using a sulfonyl chloride R6SO 2 Cl in the presence of a base, to the corresponding compound of formula Ia, where, in the compounds of formulae IIa, IIIa and IVa, Ar, X, n and R1 to R4 are each as defined in formula Ia and R6 is phenyl which is unsubstituted or substituted by methyl, trifluoromethyl, F, Cl or Br.