Provided are a method and an apparatus for producing 1,2,3,4-tetrachlorobutane that are unlikely to lose 3,4-dichloro-1-butene as the material or 1,2,3,4-tetrachlorobutane as the product and can be stably and economically produce 1,2,3,4-tetrachlorobutane. A reaction liquid (1) containing 3,4-dichloro-1-butene is placed in a reaction container (11), then chlorine gas is supplied to a gas phase (2) in the reaction container (11), and the 3,4-dichloro-1-butene is reacted with the chlorine gas to give 1,2,3,4-tetrachlorobutane.

Provided are a method and an apparatus for producing 1,2,3,4-tetrachlorobutane that are unlikely to lose 3,4-dichloro-1-butene as the material or 1,2,3,4-tetrachlorobutane as the product and can be stably and economically produce 1,2,3,4-tetrachlorobutane. A reaction liquid (1) containing 3,4-dichloro-1-butene is placed in a reaction container (11), then chlorine gas is supplied to a gas phase (2) in the reaction container (11), and the 3,4-dichloro-1-butene is reacted with the chlorine gas to give 1,2,3,4-tetrachlorobutane.

The present invention provides a process for preparing a diester compound of the following general formula (1), having a dimethylcyclobutane ring, wherein R.sup.1 and R.sup.2 represent, independently of each other, a monovalent hydrocarbon group having 1 to 10 carbon atoms, the process comprising reacting a dimethylcyclobutanone compound of the following general formula (2), wherein R.sup.1 is as defined above, with a phosphonic ester compound of the following general formula (3), wherein R.sup.2 and R.sup.3 represent, independently of each other, a monovalent hydrocarbon group having 1 to 10 carbon atoms, to produce the diester compound (1), having a dimethylcyclobutane ring.

##STR00001##

The present invention provides a process for preparing a diester compound of the following general formula (1), having a dimethylcyclobutane ring, wherein R.sup.1 and R.sup.2 represent, independently of each other, a monovalent hydrocarbon group having 1 to 10 carbon atoms, the process comprising reacting a dimethylcyclobutanone compound of the following general formula (2), wherein R.sup.1 is as defined above, with a phosphonic ester compound of the following general formula (3), wherein R.sup.2 and R.sup.3 represent, independently of each other, a monovalent hydrocarbon group having 1 to 10 carbon atoms, to produce the diester compound (1), having a dimethylcyclobutane ring.

##STR00001##

A process for producing a chlorinated alkane in which an alkene or an alkane feedstock is contacted with chlorine in a chlorination zone to produce a reaction mixture containing the chlorinated alkane, wherein the chlorine supplied into the chlorination zone has an oxygen content of less than about 2000 ppmv and wherein: the chlorination zone is closed to the atmosphere, and/or the chlorination zone is operated under atmospheric or superatmospheric pressure, and/or the chlorination zone is operated under an inert atmosphere, and/or the content of dissolved oxygen in the alkene or alkane feedstock is less than 2000 ppm.

A process for producing a chlorinated alkane in which an alkene or an alkane feedstock is contacted with chlorine in a chlorination zone to produce a reaction mixture containing the chlorinated alkane, wherein the chlorine supplied into the chlorination zone has an oxygen content of less than about 2000 ppmv and wherein: the chlorination zone is closed to the atmosphere, and/or the chlorination zone is operated under atmospheric or superatmospheric pressure, and/or the chlorination zone is operated under an inert atmosphere, and/or the content of dissolved oxygen in the alkene or alkane feedstock is less than 2000 ppm.

Disclosed are 7,7-dihalo-3,3,3,3-tetramethyl-1,1-spirobiindane and a preparation method thereof. The 7,7-dihalo-3,3,3,3-tetramethyl-1,1-spirobiindane is a compound represented by formula I, or an enantiomer, a raceme or a diastereomer thereof. The compound of formula I could be prepared by using a racemic or optically active 3,3,3,3-tetramethyl-1,1-spirobiindane-6,6-diol as a raw material through a series of reactions. The 7,7-dihalo-3,3,3,3-tetramethyl-1,1-spirobiindane is a key intermediate for preparing 3,3,3,3-tetramethyl-1,1-spirobiindane-based phosphine ligand compounds represented by formula II or III. ##STR00001##

Disclosed are 7,7-dihalo-3,3,3,3-tetramethyl-1,1-spirobiindane and a preparation method thereof. The 7,7-dihalo-3,3,3,3-tetramethyl-1,1-spirobiindane is a compound represented by formula I, or an enantiomer, a raceme or a diastereomer thereof. The compound of formula I could be prepared by using a racemic or optically active 3,3,3,3-tetramethyl-1,1-spirobiindane-6,6-diol as a raw material through a series of reactions. The 7,7-dihalo-3,3,3,3-tetramethyl-1,1-spirobiindane is a key intermediate for preparing 3,3,3,3-tetramethyl-1,1-spirobiindane-based phosphine ligand compounds represented by formula II or III. ##STR00001##

A process for producing a chlorinated alkane in which an alkene or an alkane feedstock is contacted with chlorine in a chlorination zone to produce a reaction mixture containing the chlorinated alkane, wherein the chlorine supplied into the chlorination zone has an oxygen content of less than about 2000 ppmv and wherein: the chlorination zone is closed to the atmosphere, and/or the chlorination zone is operated under atmospheric or superatmospheric pressure, and/or the chlorination zone is operated under an inert atmosphere, and/or the content of dissolved oxygen in the alkene or alkane feedstock is less than 2000 ppm.

A process for producing a chlorinated alkane in which an alkene or an alkane feedstock is contacted with chlorine in a chlorination zone to produce a reaction mixture containing the chlorinated alkane, wherein the chlorine supplied into the chlorination zone has an oxygen content of less than about 2000 ppmv and wherein: the chlorination zone is closed to the atmosphere, and/or the chlorination zone is operated under atmospheric or superatmospheric pressure, and/or the chlorination zone is operated under an inert atmosphere, and/or the content of dissolved oxygen in the alkene or alkane feedstock is less than 2000 ppm.