Ethylenebis(hydroxyalkylphosphinic acid) and salts thereof

A process for preparing an ethylenebis (hydroxyalkylphosphinic acid) or salt thereof having the formula (I)

• A-P(O)(OX)—CR1R2—CR3R4—P(O)(OX)-A (I)
• wherein:
• A is CR5R6—OH;
• R1, R2, R3, and R4 are H;
• R5 and R6 are independently selected from the group consisting of H, C1-C20-alkyl, C6-C20-aryl, and C6-C20-aralkyl;
• and
• X is H or an alkali metal;
• said process comprising the steps of:
• a) reacting acetylene with a monophosphinic acid adduct of the formula (II)
• H—P(O)(OX)-A (II);
• and
• b) optionally separating the resulting ethylenebis(hydroxyalkylphosphinic acid) or salt thereof from reaction by-products.

A process for preparing a salt of ethylenebis (hydroxyalkylphosphinic acid) of the type

• A-P(O)(OX)-CR1R2—CR3R4—P(O)(OX)-A
• wherein:
• A is CR5R6—OH;
• each R1, R2, R3, R4, R5, and R6 is independently selected from the group consisting of H, C1-C20-alkyl, C6-C20-aryl, and C6-C20-aralkyl, so long as at least one of R1 and R2 and at least one of R3 and R4 is H;
• and
• X is selected from the group consisting of an alkali metal, an element of main group or transition group 2, an element of main or transition group 3, an element of main or transition group 4, an element of main or transition group 5, an element of transition group 6, an element of transition group 7, an element of transition group 8, and a nitrogen base;
• said process comprising the step of reacting a reactant I with an ethylenebis (hydroxyalkylphosphinic acid) in a solvent system;
• wherein said ethylenebis(hydroxyalkylphosphinic acid) is of the type
• A-P(O)(OX)-CR1R2—CR3R4—P(O)(OX)-A
• wherein:
• A is CR5R6—OH;
• each R1, R2, R3, R4, R5, and R6 is independently selected from the group consisting of H, C1-C20-alkyl, C6-C20-aryl, and C6-C20-aralkyl, so long as at least one of R1 and R2 and at least one of R3 and R4 is H;
• and
• X is H;
• and
• wherein reactant I is selected from the group consisting of a compound of an alkali metal, a compound of an element of main or transition group 2, a compound of an element of main or transition group 3, a compound of an element of main or transition group 4, a compound of an element of main or transition group 5, a compound of an element of transition group 6, a compound of an element of transition group 7, a compound of an element of transition group 8, and a nitrogen base.

A process for preparing a salt of ethylenebis (hydroxyalkylphosphinic acid) of the type

• A-P(O)(OX)-CR1R2—CR3R4—P(O)(OX)-A
• wherein:
• A is CR5R6—OH;
• each R1, R2, R3, R4, R5, and R6 is independently selected from the group consisting of H, C1-C20-alkyl, C6-C20-aryl, and C6-C20-aralkyl, so long as at least one of R1 and R2 and at least one of R3 and R4 is H;
• and
• X is selected from the group consisting of an element of main group or transition group 2, an element of main or transition group 3, an element of main or transition group 4, an element of main or transition group 5, an element of transition group 6, an element of transition group 7, an element of transition group 8, and a nitrogen base;
• said process comprising the step of reacting a reactant II with a salt of an ethylenebis (hydroxyalkylphosphinic acid) in a solvent system;
• wherein said salt of an ethylenebis(hydroxyalkylphosphinic acid) is of the type
• A-P(O)(OX)-CR1R2—CR3R4—P(O)(OX)-A
• wherein:
• A is CR5R6—OH;
• each R1, R2, R3, R4, R5, and R6 is independently selected from the group consisting of H, C1-C20-alkyl, C6-C20-aryl, and C6-C20-aralkyl, so long as at least one of R1 and R2 and at least one of R3 and R4 is H;
• and
• X is an alkali metal;
• and
• wherein reactant II is selected from the group consisting of a compound of an element of main or transition group 2, a compound of an element of main or transition group 3, a compound of an element of main or transition group 4, a compound of an element of main or transition group 5, a compound of an element of transition group 6, a compound of an element of transition group 7, a compound of an element of transition group 8, and a nitrogen base.