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##

An isocyanate production method is characterized by having: a carbamation step in which a carbonic acid ester, an inorganic acid salt of an amino acid derivative, and a basic compound are reacted to obtain a reaction mixture containing a carbamic acid ester derived from the carbonic acid ester, a hydroxy compound derived from the carbonic acid ester, and the carbonic acid ester; and a thermal decomposition step in which the carbamic acid ester is subjected to a thermal decomposition reaction to obtain an isocyanate.

An isocyanate production method is characterized by having: a carbamation step in which a carbonic acid ester, an inorganic acid salt of an amino acid derivative, and a basic compound are reacted to obtain a reaction mixture containing a carbamic acid ester derived from the carbonic acid ester, a hydroxy compound derived from the carbonic acid ester, and the carbonic acid ester; and a thermal decomposition step in which the carbamic acid ester is subjected to a thermal decomposition reaction to obtain an isocyanate.

An isocyanate production method is characterized by having: a carbamation step in which a carbonic acid ester, an inorganic acid salt of an amino acid derivative, and a basic compound are reacted to obtain a reaction mixture containing a carbamic acid ester derived from the carbonic acid ester, a hydroxy compound derived from the carbonic acid ester, and the carbonic acid ester; and a thermal decomposition step in which the carbamic acid ester is subjected to a thermal decomposition reaction to obtain an isocyanate.

Provided is a process for preparing an organic diisocyanate of the formula: OCN—R—NCO (1), wherein R represents a bivalent hydrocarbon radical containing 3 to 20 carbon atoms, the carbon atoms being arranged in a way that the two nitrogen atoms are separated from each other by at least 3 carbon atoms, the process comprising, Step (I) preparing a diurethane of the formula ##STR00001##
wherein R is the same as in formula (1), R′ and R″ independently represent organic radicals selected from the group consisting of 4 to 36 carbon atoms, 4 to 74 hydrogen atoms, 0 to 12 oxygen atoms that have the oxidation state −2, and 0 to 1 halogen atoms from a diarylurethane of the formula, ##STR00002##
wherein R is the same as in formula (1), Ar and Ar′ independently represent a substituted or unsubstituted aryl or heteroaryl radical selected from the group containing a total of 4 to 20 carbon atoms by transesterification, Step (II) subjecting the diurethane of the formula (2) to a cleavage reaction to form the hydroxy compounds R′—OH and R″—OH and the organic diisocyanate of the formula (1), Step (III) separating the diisocyanate of the formula (1) from the hydroxy compounds R′—OH and R″—OH by distillation, wherein the hydroxy compounds R′—OH and R″—OH have higher standard boiling points than the standard boiling point of the diisocyanate OCN—R—NCO and the sum of the molecular weights of the radicals Ar and Ar′ is lower than the sum of the molecular weights of the radicals R′ and R″.

Provided is a process for preparing an organic diisocyanate of the formula: OCN—R—NCO (1), wherein R represents a bivalent hydrocarbon radical containing 3 to 20 carbon atoms, the carbon atoms being arranged in a way that the two nitrogen atoms are separated from each other by at least 3 carbon atoms, the process comprising, Step (I) preparing a diurethane of the formula ##STR00001##
wherein R is the same as in formula (1), R′ and R″ independently represent organic radicals selected from the group consisting of 4 to 36 carbon atoms, 4 to 74 hydrogen atoms, 0 to 12 oxygen atoms that have the oxidation state −2, and 0 to 1 halogen atoms from a diarylurethane of the formula, ##STR00002##
wherein R is the same as in formula (1), Ar and Ar′ independently represent a substituted or unsubstituted aryl or heteroaryl radical selected from the group containing a total of 4 to 20 carbon atoms by transesterification, Step (II) subjecting the diurethane of the formula (2) to a cleavage reaction to form the hydroxy compounds R′—OH and R″—OH and the organic diisocyanate of the formula (1), Step (III) separating the diisocyanate of the formula (1) from the hydroxy compounds R′—OH and R″—OH by distillation, wherein the hydroxy compounds R′—OH and R″—OH have higher standard boiling points than the standard boiling point of the diisocyanate OCN—R—NCO and the sum of the molecular weights of the radicals Ar and Ar′ is lower than the sum of the molecular weights of the radicals R′ and R″.

Provided is a process for preparing an organic diisocyanate of the formula: OCN—R—NCO (1), wherein R represents a bivalent hydrocarbon radical containing 3 to 20 carbon atoms, the carbon atoms being arranged in a way that the two nitrogen atoms are separated from each other by at least 3 carbon atoms, the process comprising, Step (I) preparing a diurethane of the formula ##STR00001##
wherein R is the same as in formula (1), R′ and R″ independently represent organic radicals selected from the group consisting of 4 to 36 carbon atoms, 4 to 74 hydrogen atoms, 0 to 12 oxygen atoms that have the oxidation state −2, and 0 to 1 halogen atoms from a diarylurethane of the formula, ##STR00002##
wherein R is the same as in formula (1), Ar and Ar′ independently represent a substituted or unsubstituted aryl or heteroaryl radical selected from the group containing a total of 4 to 20 carbon atoms by transesterification, Step (II) subjecting the diurethane of the formula (2) to a cleavage reaction to form the hydroxy compounds R′—OH and R″—OH and the organic diisocyanate of the formula (1), Step (III) separating the diisocyanate of the formula (1) from the hydroxy compounds R′—OH and R″—OH by distillation, wherein the hydroxy compounds R′—OH and R″—OH have higher standard boiling points than the standard boiling point of the diisocyanate OCN—R—NCO and the sum of the molecular weights of the radicals Ar and Ar′ is lower than the sum of the molecular weights of the radicals R′ and R″.

An organic-inorganic hybrid material is disclosure. The organic-inorganic hybrid material contains 5˜50 wt % of inorganic compounds and has a characteristic peak at 1050±50 cm.sup.−1 in FTIR spectrum. Furthermore, the invention also provides a fabricating process of the organic-inorganic hybrid material as well as its starting material “isocyanates”. In particular, the isocyanates are prepared from carbonate containing compounds and amines.

An organic-inorganic hybrid material is disclosure. The organic-inorganic hybrid material contains 5˜50 wt % of inorganic compounds and has a characteristic peak at 1050±50 cm.sup.−1 in FTIR spectrum. Furthermore, the invention also provides a fabricating process of the organic-inorganic hybrid material as well as its starting material “isocyanates”. In particular, the isocyanates are prepared from carbonate containing compounds and amines.

Disclosed is a preparation method for preparing diphenylmethane diisocyanate. The preparation method comprises: under a catalyst condition, performing a pyrolysis reaction on diphenylmethane dicarbamate in an inert solvent having a boiling point lower than that of diphenylmethane diisocyanate to obtain diphenylmethane diisocyanate.