The present invention relates to a process for synthesizing large scale a compound of formula (I), or pharmacuetically acceptable salt thereof, which is useful as the key intermediate for the synthesis of compounds for prophylaxis and treatment of a disease associated with the deposition of β-amyloid in the brain, in particular Alzheimer's disease, and other diseases such as cerebral amyloid angiopathy, hereditary cerebral hemorrhage with amyloidosis, Dutch-type (HCHWA-D), multi-infarct dementia, dementia pugilistica and Down syndrome.

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The present invention relates to a process for synthesizing large scale a compound of formula (I), or pharmacuetically acceptable salt thereof, which is useful as the key intermediate for the synthesis of compounds for prophylaxis and treatment of a disease associated with the deposition of β-amyloid in the brain, in particular Alzheimer's disease, and other diseases such as cerebral amyloid angiopathy, hereditary cerebral hemorrhage with amyloidosis, Dutch-type (HCHWA-D), multi-infarct dementia, dementia pugilistica and Down syndrome.

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A continuous flow process (CFP) for the production of an acid chloride includes the following steps: (i) providing or forming a first reactant comprising a chlorine-donating compound; (ii) providing or forming a second reactant comprising a carboxylic acid; (iii) providing a first continuous flow of the first reactant into a reactor at a first flow rate; (iv) providing a second continuous flow of the second reactant into the reactor at a second flow rate; and (v) mixing the first reactant and the second reactant in a portion of the reactor and reacting the first reactant and the second reactant to provide a reaction product comprising an acid chloride.

A continuous flow process (CFP) for the production of an acid chloride includes the following steps: (i) providing or forming a first reactant comprising a chlorine-donating compound; (ii) providing or forming a second reactant comprising a carboxylic acid; (iii) providing a first continuous flow of the first reactant into a reactor at a first flow rate; (iv) providing a second continuous flow of the second reactant into the reactor at a second flow rate; and (v) mixing the first reactant and the second reactant in a portion of the reactor and reacting the first reactant and the second reactant to provide a reaction product comprising an acid chloride.

Provided is a process for preparing 4-phenyl-1-butyric acid, comprising: reacting 4-phenyl-1-butanol with sodium chlorite, a nitroxyl radical catalyst and sodium hypochlorite in an organic solvent and a phosphate buffer; and quenching the reaction with sodium sulfite to produce 4-phenyl-1-butyric. Also provided is 4-phenyl-1-butyric acid prepared by such a process.

Provided is a process for preparing 4-phenyl-1-butyric acid, comprising: reacting 4-phenyl-1-butanol with sodium chlorite, a nitroxyl radical catalyst and sodium hypochlorite in an organic solvent and a phosphate buffer; and quenching the reaction with sodium sulfite to produce 4-phenyl-1-butyric. Also provided is 4-phenyl-1-butyric acid prepared by such a process.

Clean process for preparing a chloroformyl-substituted benzene by oxidation of a tail gas hydrogen chloride from a chlorination reaction and a chloroacylation reaction and recycling of the resulting oxidation product chlorine gas into the chlorination reaction. The present invention provides a clean process for preparing a polymer-grade chloroformyl-substituted benzene.

Clean process for preparing a chloroformyl-substituted benzene by oxidation of a tail gas hydrogen chloride from a chlorination reaction and a chloroacylation reaction and recycling of the resulting oxidation product chlorine gas into the chlorination reaction. The present invention provides a clean process for preparing a polymer-grade chloroformyl-substituted benzene.

The present invention discloses recyclable polymeric catalyst of Formula I, for chlorination of organic acids and alcohols using chlorinating agents such as carbonyl chloride, oxalyl chloride or thionyl chloride,

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wherein, ‘m’ on the pendent groups on polystyrene backbone can have values from 1 to 5 and R is the alkyl group ranging from C1 to C5.

The present invention discloses recyclable polymeric catalyst of Formula I, for chlorination of organic acids and alcohols using chlorinating agents such as carbonyl chloride, oxalyl chloride or thionyl chloride,

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wherein, ‘m’ on the pendent groups on polystyrene backbone can have values from 1 to 5 and R is the alkyl group ranging from C1 to C5.