An economic, one-step method for the production of N-substituted aromatic hydroxylamines of formula (I)

RN(OH)C(O)(O)R.sub.1(I),

with hydrogen, by catalytic hydration with possibly modified hydration catalysts in an aprotic solvent and in the presence of a halogen formic acid ester and in some cases in the presence of a base.

An economic, one-step method for the production of N-substituted aromatic hydroxylamines of formula (I)

RN(OH)C(O)(O)R.sub.1(I),

with hydrogen, by catalytic hydration with possibly modified hydration catalysts in an aprotic solvent and in the presence of a halogen formic acid ester and in some cases in the presence of a base.

The present invention relates to the compound 2-ethyl-5,5-dimethyl-cyclohexanol, which can impart, modify and/or enhance one or more odours selected from the group consisting of minty, fresh tobacco leaf, cresol, horse and animalistic, mixtures comprising 2-ethyl-5,5-dimethyl-cyclohexanol, and a new method for producing the same, a fragrance composition comprising 2-ethyl-5,5-dimethyl-cyclohexanol, the use of 2-ethyl-5,5-dimethyl-cyclohexanol as a fragrance, particularly for imparting, modifying and/or enhancing one or more odours selected from the group consisting of minty, fresh tobacco leaf, cresol, horse and animalistic, a perfumed product comprising 2-ethyl-5,5-dimethyl-cyclohexanol, a method for perfuming such a product and a method for modifying an olfactory impression.

The present invention relates to the compound 2-ethyl-5,5-dimethyl-cyclohexanol, which can impart, modify and/or enhance one or more odours selected from the group consisting of minty, fresh tobacco leaf, cresol, horse and animalistic, mixtures comprising 2-ethyl-5,5-dimethyl-cyclohexanol, and a new method for producing the same, a fragrance composition comprising 2-ethyl-5,5-dimethyl-cyclohexanol, the use of 2-ethyl-5,5-dimethyl-cyclohexanol as a fragrance, particularly for imparting, modifying and/or enhancing one or more odours selected from the group consisting of minty, fresh tobacco leaf, cresol, horse and animalistic, a perfumed product comprising 2-ethyl-5,5-dimethyl-cyclohexanol, a method for perfuming such a product and a method for modifying an olfactory impression.

A process of forming compounds of formula I ##STR00001##
comprising the steps of addition of an amino compound H.sub.2NR to a compound of formula (II) ##STR00002##
followed by cyclization, isomerization and hydrolysis.

The present invention discloses an improved catalyst free process for synthesis of alkyl carbamates in an integrated system comprising a tubular reactor and a striper. The process comprises reacting urea and an alcohol in said tubular reactor under autogeneous pressure; wherein said process provides >90% selectivity towards alkyl carbamate. The mixture of urea and alcohol is N fed to the tubular reactor at a particular feed rate. The tubular reactor is heated externally under autogeneous pressure to carry out a synthesis reaction producing alkyl carbamate and ammonia. The ammonia is removed from the tubular reactor by the striper. The tubular reactor and the stripper are arranged in series to reduce the equilibrium limitations of the reaction and drive the reaction in forward direction.

The present invention discloses an improved catalyst free process for synthesis of alkyl carbamates in an integrated system comprising a tubular reactor and a striper. The process comprises reacting urea and an alcohol in said tubular reactor under autogeneous pressure; wherein said process provides >90% selectivity towards alkyl carbamate. The mixture of urea and alcohol is N fed to the tubular reactor at a particular feed rate. The tubular reactor is heated externally under autogeneous pressure to carry out a synthesis reaction producing alkyl carbamate and ammonia. The ammonia is removed from the tubular reactor by the striper. The tubular reactor and the stripper are arranged in series to reduce the equilibrium limitations of the reaction and drive the reaction in forward direction.

The present invention discloses an improved catalyst free process for synthesis of alkyl carbamates in an integrated system comprising a tubular reactor and a striper. The process comprises reacting urea and an alcohol in said tubular reactor under autogeneous pressure; wherein said process provides >90% selectivity towards alkyl carbamate. The mixture of urea and alcohol is N fed to the tubular reactor at a particular feed rate. The tubular reactor is heated externally under autogeneous pressure to carry out a synthesis reaction producing alkyl carbamate and ammonia. The ammonia is removed from the tubular reactor by the striper. The tubular reactor and the stripper are arranged in series to reduce the equilibrium limitations of the reaction and drive the reaction in forward direction.

The invention provides methods of synthesizing compounds in an asymmetric or enantioenriched fashion, wherein the compounds are useful intermediates in the synthesis of viral protease inhibitors.

The invention provides methods of synthesizing compounds in an asymmetric or enantioenriched fashion, wherein the compounds are useful intermediates in the synthesis of viral protease inhibitors.