The diamine composition according to an embodiment of the present invention comprises a benzylmonoamine having a methyl group in an amount of 10 ppm to 2,000 ppm in the composition. When it is used for the preparation of a diisocyanate composition and an optical material, it is possible to improve the optical characteristics by preventing the occurrence of yellowing, striae, and cloudiness in the optical material and enhancing the mechanical properties such as impact resistance at the same time. In addition, in the process for preparing a diisocyanate composition according to another embodiment, the b* value according to the CIE color coordinate of a diamine composition is adjusted to a specific range, whereby it is possible to enhance not only the yield and purity of the diisocyanate composition but also the optical characteristics of the final optical lens. Thus, the process for preparing a diisocyanate composition can be applied to the preparation of a plastic optical lens of high quality.

The diamine composition according to an embodiment of the present invention comprises a benzylmonoamine having a methyl group in an amount of 10 ppm to 2,000 ppm in the composition. When it is used for the preparation of a diisocyanate composition and an optical material, it is possible to improve the optical characteristics by preventing the occurrence of yellowing, striae, and cloudiness in the optical material and enhancing the mechanical properties such as impact resistance at the same time. In addition, in the process for preparing a diisocyanate composition according to another embodiment, the b* value according to the CIE color coordinate of a diamine composition is adjusted to a specific range, whereby it is possible to enhance not only the yield and purity of the diisocyanate composition but also the optical characteristics of the final optical lens. Thus, the process for preparing a diisocyanate composition can be applied to the preparation of a plastic optical lens of high quality.

The embodiments provide processes for preparing a diisocyanate composition and an optical lens, which are excellent in yield and quality with mitigated environmental problems by using a solid triphosgene composition instead of phosgene gas in the process of preparing a diisocyanate from a diamine through a hydrochloride thereof and by controlling the content of a decomposition product in a triphosgene composition, the b* value according to CIE color coordinate of the triphosgene composition in an organic solvent, or the content of water in the triphosgene.

The embodiments provide processes for preparing a diisocyanate composition and an optical lens, which are excellent in yield and quality with mitigated environmental problems by using a solid triphosgene composition instead of phosgene gas in the process of preparing a diisocyanate from a diamine through a hydrochloride thereof and by controlling the content of a decomposition product in a triphosgene composition, the b* value according to CIE color coordinate of the triphosgene composition in an organic solvent, or the content of water in the triphosgene.

An embodiment relates to an isocyanate composition with improved stability and reactivity and a plastic optical lens using the same. The isocyanate composition has improved stability since the content of chlorine in the composition is adjusted to 22-500 ppm, and thus the isocyanate composition can prevent the deterioration in reactivity even in the long-term storage. Therefore, the isocyanate composition according to an example, even when used after long-term storage after preparation, can be prepared, through polymerization with a thiol-based compound, as a polythiourethane-based optical material with excellent physical properties, such as refractive index, Abbe number, transparency, glass transition temperature, and yellowness, and thus the isocyanate composition is useful in fields of glass lenses, a camera lens, and the like.

Disclosed is a process for the synthesis of pimavanserin base with a high yield and purity, which comprises: a) converting tert-butyl-N-[(4-propan-2-yloxyphenyl)methyl]carbamate (Formula (I)) to 1-(isocyanatomethyl)-4-propan-2-yloxybenzene of formula (II) b) adding N-[(4-fluorophenyl)methyl]-1-methylpiperidin-4-amine (Formula (IV)) to the solution obtained in a) to give pimavanserin base, and c) purifying the pimavanserin base obtained in step b).

##STR00001##

Disclosed is a process for the synthesis of pimavanserin base with a high yield and purity, which comprises: a) converting tert-butyl-N-[(4-propan-2-yloxyphenyl)methyl]carbamate (Formula (I)) to 1-(isocyanatomethyl)-4-propan-2-yloxybenzene of formula (II) b) adding N-[(4-fluorophenyl)methyl]-1-methylpiperidin-4-amine (Formula (IV)) to the solution obtained in a) to give pimavanserin base, and c) purifying the pimavanserin base obtained in step b).

##STR00001##

The present invention relates to a method for preparing an aliphatic isocyanate capable of suppressing the occurrence of side reactions and the production of by-products. The method for preparing an aliphatic isocyanate comprises a step of reacting a salt of an aliphatic amine with phosgene, wherein the reaction step comprises a first reaction step in which phosgene is primarily added and reacted with the salt of an aliphatic amine salt at a temperature of 80 to 100° C., and a second reaction step in which phosgene is secondarily added and reacted with the resultant product of the first reaction step at a temperature of 120 to 160° C., and wherein the amount of the primarily added phosgene is a certain ratio of the total amount of the phosgene.

Provided is an alkyldiphenylmethane protective agent, which can prevent solidification or insolubilization of a compound by protecting a functional group of the compound to achieve easy separation and purification after a reaction.

An alkyldiphenylmethane compound represented by general formula (1):

##STR00001## wherein Y represents OR.sup.19 (wherein R.sup.19 represents a hydrogen atom or an active ester-type protecting group), NHR.sup.20 (wherein R.sup.20 represents a hydrogen atom, a C.sub.1-6 linear or branched alkyl group, or an aralkyl group), isocyanate group, an azide group, or a halogen atom, Z represents a C.sub.1-4 linear or branched alkyl group, an alkenyl group, or a cycloalkyl group, at least one of R.sup.1 to R.sup.10 represents a group represented by formula (2):

OR.sup.11X-A(2) and the others each independently represent a hydrogen atom, a halogen atom, a C.sub.1-4 alkyl group, or a C.sub.1-4 alkoxy group; R.sup.11 represents a C.sub.1-16 linear or branched alkylene group; X represents O or CONR.sup.21 (wherein R.sup.21 represents a hydrogen atom or a C.sub.1-4 alkyl group); and A represents, for example, a group represented by formula (3):

##STR00002## wherein R.sup.12, R.sup.13, and R.sup.14 may be the same or different and each independently represent a C.sub.1-6 linear or branched alkyl group or an optionally substituted aryl group; R.sup.15 represents a single bond or a C.sub.1-3 linear or branched alkylene group; and R.sup.16, R.sup.17, and R.sup.18 each independently represent a C.sub.1-3 linear or branched alkylene group.

Provided is an alkyldiphenylmethane protective agent, which can prevent solidification or insolubilization of a compound by protecting a functional group of the compound to achieve easy separation and purification after a reaction.

An alkyldiphenylmethane compound represented by general formula (1):

##STR00001## wherein Y represents OR.sup.19 (wherein R.sup.19 represents a hydrogen atom or an active ester-type protecting group), NHR.sup.20 (wherein R.sup.20 represents a hydrogen atom, a C.sub.1-6 linear or branched alkyl group, or an aralkyl group), isocyanate group, an azide group, or a halogen atom, Z represents a C.sub.1-4 linear or branched alkyl group, an alkenyl group, or a cycloalkyl group, at least one of R.sup.1 to R.sup.10 represents a group represented by formula (2):

OR.sup.11X-A(2) and the others each independently represent a hydrogen atom, a halogen atom, a C.sub.1-4 alkyl group, or a C.sub.1-4 alkoxy group; R.sup.11 represents a C.sub.1-16 linear or branched alkylene group; X represents O or CONR.sup.21 (wherein R.sup.21 represents a hydrogen atom or a C.sub.1-4 alkyl group); and A represents, for example, a group represented by formula (3):

##STR00002## wherein R.sup.12, R.sup.13, and R.sup.14 may be the same or different and each independently represent a C.sub.1-6 linear or branched alkyl group or an optionally substituted aryl group; R.sup.15 represents a single bond or a C.sub.1-3 linear or branched alkylene group; and R.sup.16, R.sup.17, and R.sup.18 each independently represent a C.sub.1-3 linear or branched alkylene group.