- Transition-metal-free decarboxylative halogenation of 2-picolinic acids with dihalomethane under oxygen conditions
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A convenient and efficient method for the synthesis of 2-halogen-substituted pyridines is described. The decarboxylative halogenation of 2-picolinic acids with dihalomethane proceeded smoothly via N-chlorocarbene intermediates to afford 2-halogen-substituted pyridines in satisfactory to excellent yields under transition-metal-free conditions. This new type of decarboxylative halogenation is operationally simple and exhibits high functional-group tolerance.
- Zhang, Xitao,Feng, Xiujuan,Zhang, Haixia,Yamamoto, Yoshinori,Bao, Ming
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supporting information
p. 5565 - 5570
(2019/10/22)
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- Reaction of N-fluoropyridinium fluoride with isonitriles: A convenient route to picolinamides
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Reaction of N-fluoropyridinium fluoride generated in situ with a series of isonitriles led to the formation of the corresponding picolinamides in good yields. A similar reaction sequence for quinoline yielded the respective derivatives of 2-quinoline carboxylic acid. The proposed reaction mechanism involves the intermediate formation of a highly reactive carbene species.
- Kiselyov, Alexander S.
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p. 2279 - 2282
(2007/10/03)
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- Unusual C-6 lithiation of 2-chloropyridine-mediated by BuLi-Me2N(CH2)2OLi. New access to 6-functional-2-chloropyridines and chloro-bis-heterocycles
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Formula Presented The reaction of 2-chloropyridine with alkylithium generally results in nucleophilic addition leading to the loss of chlorine atom while exclusive directed ortho metalation is obtained using LDA. Herein it is shown that the BuLi-Me2
- Choppin, Sabine,Gros, Philippe,Fort, Yves
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p. 803 - 805
(2007/10/03)
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- Substituent Effect on the Chlorination of 2-Alkoxypyridines to give 2-Chloropyridines under Vilsmeier-Haack Conditions
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Various substituted 2-alkoxypyridines were converted into the corresponding 2-chloropyridines in 28-91% yields by use of POCl3 and DMF, in which the methyl, halogen, ester and nitro groups displayed an activating effect; in contrast, an amino group exhibited a deactivating effect.
- Lai, Long-Li,Lin, Pen-Yuan,Wang, Jy-Shih,Hwu, Jih Ru,Shiao, Min-Jen,Tsay, Shwu-Chen
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p. 194 - 195
(2007/10/03)
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- Pyridylthio-acylanilide herbicides
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Novel herbicidally active pyridylthio-acylanilides of the formula STR1 in which R1, R2 and R3, independently of one another, represent hydrogen, halogen, cyano or trifluoromethyl or alkyl, alkoxy and alkylthio having 1 to 4 carbon atoms in each case, R4 represents halogen, methyl or methoxy, n represents a number 0, 1 or 2, z represents the group (Ia) STR2 or the group (Ib) STR3 where X represents oxygen, sulphur, an N--R10 or N--O--R11 group, or X and Rg tpgether represent the STR4 radical, and the other radicals can have various meanings. Intermediates of the formulae STR5 are also new.
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- Pyri(mi)dyl-oxy-and -thio-benzoic acid derivatives useful as herbicides and plant growth regulants
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New pyri(mi)dyl-oxy- or -thio-benzoic acid derivatives of the formula STR1 are taught which have herbicidal and plant growth regulating activity. In the formula Z can be Ch or N, X is oxygen or sulphur, A is oxygen, sulphur, a radical R5 --N=or a radical R6 O--N=and B is oxygen, sulphur, a radical STR2 with the proviso that at least one of the radicals R1, R2 or R3 represents alkyl or a part of a 3- to 6-membered fused carbocyclic ring.
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- 2-halo-pyridines
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2-Halo-pyridines of the general formula I STR1 wherein X is Cl or Br; A is =0 or STR2 Ar is phenyl or substituted phenyl of the general formula STR3 in which n is 0, 1, 2 or 3; R is alkyl C1-4, alkoxy C1-4, phenoxy, alkylthio C1-4, halogen especially F and Cl, OH or C6 H5 ; and their salts, addition compounds and precursors (prodrugs). Furthermore the invention is directed to the production of these compounds and pharmaceuticals containing them.
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