Propenimidates, their preparation and rearrangement to pyrimidines
AssigneeE. I. Du Pont de Nemours and Company
InventorJulius J. Fuchs
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Abstract
Propenimidates are provided having the formula: ##STR1## wherein X and Y are independently O or S; and R.sup.1 and R.sup.2 are independently C.sub.1 -C.sub.4 alkyl, (CH.sub.2).sub.n OR.sup.3 where R.sup.3 is C.sub.1 -C.sub.4 alkyl and n is 1 or 2, CH.sub.2 CH.sub.2 Cl, or CH.sub.2 CF.sub.3, provided that when R or R.sup.2 is CH.sub.2 CH.sub.2 Cl or CH.sub.2 CF.sub.3, then the respective X or Y is O. Preferred propenimidates have X and Y as O and R.sup.1 and R.sup.2 as methyl or ethyl. The propenimidates are made by preparing a monohydrohalide salt from a dihydrohalide salt of the formula: ##STR2## and then contacting the monohydrohalide salt with cyanamide. The propenimidates upon heating ring close to pyrimidines which are useful in preparing herbicidal compounds.
Claims7
A process for preparing a compound of the formula:
- ##STR19## wherein X and Y are independently O or S;
- and
- R.sup.1 and R.sup.2 are independently C.sub.1 -C.sub.4 alkyl, (CH.sub.2).sub.n OR.sup.3 where R.sup.3 is C.sub.1 -C.sub.4 alkyl and n is 1 or 2, CH.sub.2 CH.sub.2 Cl or CH.sub.2 CF.sub.3,
- provided that when R.sup.1 of R.sup.2 is CH.sub.2 CH.sub.2 Cl or CH.sub.2 CF.sub.3, then the respective X or Y is O, comprising:
- (a) contacting a dihydrohalide salt of the formula:
- ##STR20## wherein X, Y, R.sup.1 and R.sup.2 are as defined above and Z is F, Cl or Br, in an inert liquid medium with one equivalent weight of a base at a pH no higher than about 7, to produce a monohydrohalide salt;
- and,
- (b) contacting the monohydrohalide salt with cyanamide.
A process for preparing the compound of the formula:
- ##STR21## comprising:
- (a) contacting a dihydrochloride salt of the formula:
- ##STR22## in an inert liquid medium with one equivalent weight of sodium carbonate, sodium bicarbonate or sodium hydroxide dissolved in water, at a pH of the reaction medium in the range of 5-7 and at a temperature in the range of about -10.degree. C. to above 20.degree. C.;
- and
- (b) contacting the resulting monohydrochloride salt with an aqueous solution of cyanamide at a temperature in the range of about 25.degree.-50.degree. C.
Dependencies are inferred from the claim text.