Cachaça is a sugar cane spirit produced in Brazil. Ethyl carbamate (EC), a potential carcinogenic compound, may be present in cachaça above the limit established by law. The purpose of this study was to determine the concentration of ethyl carbamate in cachaças recently produced in Brazil in order to verify their compliance with the law. The concentration of ethyl carbamate was determined in 37...

malaria has recently been resurged in some parts of iran which is bordered with armenia, naxcivan and turkey. an attempt was made to asses the current status of insecticide resistance in the main malaria vector , an.sacharovi. adult engorged mosquitoes were collected from dwellings during the seasonal activity of the vector, which is synchronized in summer 2001. mosquitoes were subjected to the...

Cycloaddition of 3,4-dibromofuran with azo diesters proceeds by a Diels–Alder reaction followed by a novel rearrangement to give 3,5dibromotetrahydropyridazin-4-ones. Variable-temperature NMR spectroscopy shows four separate conformations at low temperature attributed to restricted rotation about the carbamate functions. The ethyl compound decomposes upon storage with loss of the carbamate grou...

Abstract Novel chiral selectors based on cellulose 2,3- bis (3,5-dimethylphenyl carbamate)-6-( ? -phenylethyl carbamate) were regioselectively synthesized by carbonate aminolysis and isocyanate chemistry. By oxycarbonylation with phenyl chloroformate, carbamoylation 3,5-dimethylphenyl isocyanate, subsequent of the previously introduced reactive moiety at C6 enantiopure ( R )-or S )- -phenylethy...

In the crystal structure of the title compound, C(18)H(22)N(2)O(2), the pyridine ring makes dihedral angles of 83.71 (6) and 9.2 (1)° with the phenyl ring and the carbamate plane, respectively. The phenyl ring and the carbamate plane are nearly perpendicular to one another, with a dihedral angle of 87.17 (7)°.

To All(oc) involved: A palladium-catalyzed formal 5-endo-trig heteroannulation of enones generated in situ from amino acid derived β-keto nitriles has been realized (see scheme; Alloc=allyl carbamate). The reaction proceeds with allyl-group transfer from the carbamate protecting group to generate two new contiguous stereocenters, including one quaternary center, with high selectivity.

The methyl–amide complex [TaCp*(NBu)Me(NMe2)] (1a) was isolated by reaction of the chloro–methyl [TaCp*(NBu)MeCl] complex with LiNMe2. Reaction of the mono-amide compounds [TaCp*(N Bu)XY] (X=NMe2, Y=Me (1a); X=NHBu, Y=Me (1b), Cl (1c)) with CO2 gives the h-carbamate derivatives [TaCp*(NBu)(h-O2CX)Y] (X=NMe2, Y=Me (2a); X=NHBu, Y=Me (2b), Cl (2c)). A similar reaction with the di-amide complex [T...