Disclosed are an etelcalcetide intermediate and a method for synthesizing etelcalcetide. The etelcalcetide intermediate is Fmoc-D-Cys(S—S—(N-Boc)-L-Cys(OtBu))-OH. The method for synthesizing the etelcalcetide includes the following steps: using N-Boc-L-Cqs-OtBu as a starting material to generate a primary product of a formula (A) by means of a substitution reaction, herein R is S-Py or Cl; and performing a coupling reaction on the primary product and Fmoc-D-Cys-OH amino acid to obtain Fmoc-D-Cys(S—S—(N-Boc)-L-Cys(OtBu))-OH. The key intermediate is used for synthesizing the etelcalcetide, which may improve the purity and the yield. It is important that the raw materials for synthesizing the key intermediate are cheap and readily available, and the process is simple.

##STR00001##

Disclosed are an etelcalcetide intermediate and a method for synthesizing etelcalcetide. The etelcalcetide intermediate is Fmoc-D-Cys(S—S—(N-Boc)-L-Cys(OtBu))-OH. The method for synthesizing the etelcalcetide includes the following steps: using N-Boc-L-Cqs-OtBu as a starting material to generate a primary product of a formula (A) by means of a substitution reaction, herein R is S-Py or Cl; and performing a coupling reaction on the primary product and Fmoc-D-Cys-OH amino acid to obtain Fmoc-D-Cys(S—S—(N-Boc)-L-Cys(OtBu))-OH. The key intermediate is used for synthesizing the etelcalcetide, which may improve the purity and the yield. It is important that the raw materials for synthesizing the key intermediate are cheap and readily available, and the process is simple.

##STR00001##

The invention relates to a process for the co-production of methyl mercaptan and of dimethyl disulfide, comprising the following successive steps: a) reaction of at least one carbon oxide in the presence of hydrogen sulfide (H.sub.2S) and hydrogen to form a stream (M) comprising methyl mercaptan, water, and possibly unreacted hydrogen sulfide, b) purification of the stream (M) to obtain a stream (N) enriched in methyl mercaptan and a stream containing the uncondensable compounds (M.sub.uncond), c) optional recycling of the stream of uncondensable compounds (M.sub.uncond) obtained from step b) into step a), d) recovery of a first portion of the stream (N) including methyl mercaptan purified in step b), e) oxidation with sulfur of the second portion of the stream (N) of methyl mercaptan, to form a stream (O) comprising dimethyl disulfide, hydrogen sulfide, and possibly unreacted methyl mercaptan, f) purification of the stream (O) to separate, on the one hand, the enriched dimethyl disulfide and, on the other hand, the hydrogen sulfide and possibly the methyl mercaptan that has not reacted in step e), g) recycling of the hydrogen sulfide and possibly of the methyl mercaptan isolated in step f) into the stream (M) obtained from step a), h) recovery of the dimethyl disulfide isolated in step f).

The invention relates to a process for the co-production of methyl mercaptan and of dimethyl disulfide, comprising the following successive steps: a) reaction of at least one carbon oxide in the presence of hydrogen sulfide (H.sub.2S) and hydrogen to form a stream (M) comprising methyl mercaptan, water, and possibly unreacted hydrogen sulfide, b) purification of the stream (M) to obtain a stream (N) enriched in methyl mercaptan and a stream containing the uncondensable compounds (M.sub.uncond), c) optional recycling of the stream of uncondensable compounds (M.sub.uncond) obtained from step b) into step a), d) recovery of a first portion of the stream (N) including methyl mercaptan purified in step b), e) oxidation with sulfur of the second portion of the stream (N) of methyl mercaptan, to form a stream (O) comprising dimethyl disulfide, hydrogen sulfide, and possibly unreacted methyl mercaptan, f) purification of the stream (O) to separate, on the one hand, the enriched dimethyl disulfide and, on the other hand, the hydrogen sulfide and possibly the methyl mercaptan that has not reacted in step e), g) recycling of the hydrogen sulfide and possibly of the methyl mercaptan isolated in step f) into the stream (M) obtained from step a), h) recovery of the dimethyl disulfide isolated in step f).

The invention relates to a process for the co-production of alkyl mercaptan and of dialkyl disulfide, comprising the following successive steps: a) reaction of a C.sub.1-C.sub.4 alcohol in the presence of hydrogen sulfide (H.sub.2S) to form a stream (M) comprising an alkyl mercaptan, water, and possibly unreacted hydrogen sulfide, b) purification of the stream (M) to obtain a stream (N) enriched in alkyl mercaptan, c) recovery of a first portion of the stream (N) including the alkyl mercaptan purified in step b), d) oxidation with sulfur of the second portion of the stream (N) of alkyl mercaptan, to form a stream (O) comprising a dialkyl disulfide, hydrogen sulfide, and possibly unreacted alkyl mercaptan, e) purification of the stream (O) to separate, on the one hand, the enriched dialkyl disulfide and, on the other hand, the hydrogen sulfide and possibly the alkyl mercaptan that has not reacted in step d), f) recycling of the hydrogen sulfide and possibly of the alkyl mercaptan isolated in step e) into the stream (M) obtained from step a), g) recovery of the dialkyl disulfide isolated in step e).

The invention relates to a process for the co-production of alkyl mercaptan and of dialkyl disulfide, comprising the following successive steps: a) reaction of a C.sub.1-C.sub.4 alcohol in the presence of hydrogen sulfide (H.sub.2S) to form a stream (M) comprising an alkyl mercaptan, water, and possibly unreacted hydrogen sulfide, b) purification of the stream (M) to obtain a stream (N) enriched in alkyl mercaptan, c) recovery of a first portion of the stream (N) including the alkyl mercaptan purified in step b), d) oxidation with sulfur of the second portion of the stream (N) of alkyl mercaptan, to form a stream (O) comprising a dialkyl disulfide, hydrogen sulfide, and possibly unreacted alkyl mercaptan, e) purification of the stream (O) to separate, on the one hand, the enriched dialkyl disulfide and, on the other hand, the hydrogen sulfide and possibly the alkyl mercaptan that has not reacted in step d), f) recycling of the hydrogen sulfide and possibly of the alkyl mercaptan isolated in step e) into the stream (M) obtained from step a), g) recovery of the dialkyl disulfide isolated in step e).

The present invention relates to a process for preparing 1,1′-disulfanediylbis(4-fluoro-2-methyl-5-nitrobenzene)

##STR00001## which serves as an intermediate for the preparation of insecticidally, acaricidally and nematicidally active phenyl sulfoxides.

The present invention relates to a process for preparing 1,1′-disulfanediylbis(4-fluoro-2-methyl-5-nitrobenzene)

##STR00001## which serves as an intermediate for the preparation of insecticidally, acaricidally and nematicidally active phenyl sulfoxides.

The present invention relates to a process for preparing 1,1′-disulfanediylbis(4-fluoro-2-methyl-5-nitrobenzene)

##STR00001## which serves as an intermediate for the preparation of insecticidally, acaricidally and nematicidally active phenyl sulfoxides.

Disclosed is a method of synthesizing a (1R,2R)-nitroalcohol compound of formula (I), as shown in the following reaction scheme, including: subjecting a compound of formula (II) and a compound of formula (III) to a condensation reaction in an organic solvent in the presence of a copper complex generated in situ from a chiral (1S,2R)-amino alcohol ligand and a cupric salt to produce the (1R,2R)-nitroalcohol compound of formula (I), where R.sup.1 and R.sup.2 are defined in the same manner as that in the specification. The method involves mild reaction conditions, excellent diastereoselectivity and high chemical yield, and thus it is suitable for industrial applications. ##STR00001##