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    1.
    发明专利
    未知

    公开(公告)号：DE1200794B

    公开(公告)日：1965-09-16

    申请号：DEF0041549

    申请日：1963-12-14

    Applicant: HOECHST AG

    Inventor： RIEMENSCHNEIDER DR WILHELM ,  PROBST DR OTTO

    IPC: C07C47/04

    Abstract: In a process for the concentration of an aqueous formaldehyde solution by pressure distillation the water product discharged from the sump of the distillation column to sewerage is kept practically free from formaldehyde. The process involves bringing water to boil under a pressure of preferably 2 to 6 atmospheres in the sump, and then continually introducing the aqueous solution into the distillation column at between one quarters and four fifths of the way up the column, the solution being distilled off under this pressure at the head of the column and the vapours condensed, and the water product substantially free of formaldehyde being discharged from the sump, the water product containing a maximum of 0.2% by weight of formaldehyde. The concentration of the head product is increased by raising the reflux proportion. The basic aqueous solution introduced may include further constituents, such as methanol, formic acid, and methyl formate.

    4.
    发明专利
    未知

    公开(公告)号：DE1009178B

    公开(公告)日：1957-05-29

    申请号：DEF0010916

    申请日：1953-01-24

    Applicant: HOECHST AG

    Inventor： PROBST DR OTTO

    9.
    发明专利
    未知

    公开(公告)号：DE1277240B

    公开(公告)日：1968-09-12

    申请号：DEF0046706

    申请日：1965-07-24

    Applicant: HOECHST AG

    Inventor： PROBST DR OTTO ,  HOERNIG DR LOTHAR ,  HIRSCH DR LOTHAR

    IPC: C07C69/72

    Abstract: Acetoacetic acid methyl or ethyl ester is obtained by reacting diketene with methanol or ethanol at a pressure of 0.5 to 6 atm. gauge in the presence of 0.03 to 10%, calculated on the weight of the alcohol, of at least one tertiary amine of the formula where R1 and R2 represent C1- 3 alky radicals or R1 and R2 together form a 5- or 6-membered carbocyclic or heterocylic ring, oxygen or nitrogen being the sole hetero atom in said heterocylic ring, and Z is alkyl, cycloalkyl, alkenyl or cycloalkenyl of 8-18 carbons, or the group -(CH2)n-X, where n is a whole number of at least 2 and X is hydroxyl, sulphhydryl, an amino, monosubstituted amino or disubstituted amino group. The temperature in the reaction zone is suitably maintained above the boiling point of the alcohol under 760 mm. Hg but is maintained below 120 DEG C. In specific examples, the catalysts employed are dimethyl stearylamine and n-octadecyl-pyrrolidine.

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