The present invention relates to a process for preparing alkyl methacrylates and their conversion products which can be used in a multitude of chemical synthesis processes which can lead to a wide variety of different further processing products, and to an apparatus for performing this process.

A method of preventing polymer tar build-up in ACH production of MAA and/or MMA is described. The method is characterised in that one or more surfactants are contacted with the hydrolysis and optional esterification stage reaction medium, the said surfactants are selected from: a) C.sub.10 to C.sub.30 alcohol ethoxylates with an average of 5 to 100 ethylene oxide units per molecule; b) alkyl, hydrogen, O[CH.sub.2CH.sub.2O].sub.xH and/or O[CH.sub.2CH.sub.2CH.sub.2O].sub.x H N-substituted alkylene di- or triamines with an average of 1 to 30 total ethylene oxide and propylene oxide repeating units per molecule and wherein x and x are from 1 to 30; and c) C.sub.10 to C.sub.30 alcohol ethoxylate, propoxylates with an average of 5 to 100 total propylene oxide and ethylene oxide units per molecule, which units may be in a random, block or alternating sequence or may be a combination thereof. The method is particularly useful for preventing build-up of oligomer and polymer tar-like deposits in reaction vessels, process equipment, pipework or other parts of the acetone cyanohydrin MMA and MAA production process.

A method of preventing polymer tar build-up in ACH production of MAA and/or MMA is described. The method is characterised in that one or more surfactants are contacted with the hydrolysis and optional esterification stage reaction medium, the said surfactants are selected from: a) C.sub.10 to C.sub.30 alcohol ethoxylates with an average of 5 to 100 ethylene oxide units per molecule; b) alkyl, hydrogen, O[CH.sub.2CH.sub.2O].sub.xH and/or O[CH.sub.2CH.sub.2CH.sub.2O].sub.x H N-substituted alkylene di- or triamines with an average of 1 to 30 total ethylene oxide and propylene oxide repeating units per molecule and wherein x and x are from 1 to 30; and c) C.sub.10 to C.sub.30 alcohol ethoxylate, propoxylates with an average of 5 to 100 total propylene oxide and ethylene oxide units per molecule, which units may be in a random, block or alternating sequence or may be a combination thereof. The method is particularly useful for preventing build-up of oligomer and polymer tar-like deposits in reaction vessels, process equipment, pipework or other parts of the acetone cyanohydrin MMA and MAA production process.

A method of preventing polymer tar build-up in ACH production of MAA and/or MMA is described. The method is characterised in that one or more surfactants are contacted with the hydrolysis and optional esterification stage reaction medium, the said surfactants are selected from: a) C.sub.10 to C.sub.30 alcohol ethoxylates with an average of 5 to 100 ethylene oxide units per molecule; b) alkyl, hydrogen, O[CH.sub.2CH.sub.2O].sub.xH and/or O[CH.sub.2CH.sub.2CH.sub.2O].sub.x H N-substituted alkylene di- or triamines with an average of 1 to 30 total ethylene oxide and propylene oxide repeating units per molecule and wherein x and x are from 1 to 30; and c) C.sub.10 to C.sub.30 alcohol ethoxylate, propoxylates with an average of 5 to 100 total propylene oxide and ethylene oxide units per molecule, which units may be in a random, block or alternating sequence or may be a combination thereof. The method is particularly useful for preventing build-up of oligomer and polymer tar-like deposits in reaction vessels, process equipment, pipework or other parts of the acetone cyanohydrin MMA and MAA production process.

Methods of synthesizing a levodopa ester prodrug, salts thereof, and synthetic intermediates thereof are disclosed.

Methods of synthesizing a levodopa ester prodrug, salts thereof, and synthetic intermediates thereof are disclosed.

Methods of synthesizing a levodopa ester prodrug, salts thereof, and synthetic intermediates thereof are disclosed.