Process for producing amidine sulfonic acids
AssigneeMcNeilab, Inc.
InventorsCynthia A. Maryanoff, James N. Plampin, Robin C. Stanzione
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Abstract
An efficient synthesis of quanidines, e.g. of the formula (III), by oxidizing a thiourea, e.g. of the following formula (II): ##STR1## with H.sub.2 O.sub.2 and a molybdenum catalyst to yield an aminoiminomethane sulfonic acid which can then be reacted with an amine followed by optional transamination steps.
Claims32
A method for the synthesis of an amidine sulfonic acid which comprises oxidizing a thiourea with hydrogen peroxide in the presence of Na.sub.2 MoO.sub.4.2H.sub.2 O in the following two stages:
- (i) during addition of the hydrogen peroxide at a temperature of about 0.degree. to 15.degree. C.;
- and
- (ii) after addition of the hydrogen peroxide at a temperature of above 15.degree. to about 80.degree. C.
A method for the synthesis of an amidine sulfonic acid of the following formula (I) ##STR6## wherein R.sup.1, R.sup.2 and R.sup.3 are independently hydrogen, NH.sub.2, perhaloalkyl, perhaloaryl, NO.sub.2, an organic group or are joined to form an organic group, which comprises oxidizing a thiourea of the following formula (II):
- ##STR7## with hydrogen peroxide by the addition of Na.sub.2 MoO.sub.4.2H.sub.2 O in the following two stages:
- (i) during addition of the hydrogen peroxide at a temperature of about 0.degree. to 15.degree. C.;
- and
- (ii) after addition of the hydrogen peroxide at a temperature of above 15.degree. to about 80.degree. C.
A method for the synthesis of an amidine sulfonic acid which comprises oxidizing a thiourea with hydrogen peroxide in the presence of Na.sub.2 MoO.sub.4.2H.sub.2 O in the following two stages:
- (a) during addition of about 2 equivalents of the hydrogen peroxide at a temperature of about 0.degree. to 15.degree. C.;
- and
- (b) during addition of the third equivalent of the hydrogen peroxide at a temperature of about 20.degree. to 50.degree. C.
A method for the synthesis of an amidine sulfonic acid of the following formula (I) ##STR8## wherein R.sup.1, R.sup.2 and R.sup.3 are independently hydrogen, NH.sub.2, perhaloalkyl, perhaloaryl, NO.sub.2, an organic group or are joined to form an organic group, which comprises oxidizing a thiourea of the following formula (II):
- ##STR9## with hydrogen peroxide by the addition of Na.sub.2 MoO.sub.4.2H.sub.2 O in the following two stages:
- (a) during addition of about 2 equivalents of the hydrogen peroxide at a temperature of about 0.degree. to 15.degree. C.;
- and
- (b) during addition of the third equivalent of the hydrogen peroxide at a temperature of about 20.degree. to 50.degree. C.
Dependencies are inferred from the claim text.