Processes for preparing herbicidal N-(substituted heterocyclicaminocarbonyl)-aromatic sulfonamides

Claim 2

A process for preparing a herbicidal compound of formula (wherein A is an optionally substituted homocyclic or heterocyclic aromatic group; X is H; Cl; Br; C 1 -C 2 alkyl; CF 3 ; CH 3 O; methoxymethyl or -CH 2 CH 2 0CH 3 ; Y is Cl or Br; and Z is CH, N, C-Cl or C-CH 3 ) characterised in that an appropriate aromatic sulfonamide A-S0 2 NH 2 (wherein A is as defined above) is contacted with an isocyanate of formula (wherein X, Y and Z are as defined above).

Claim 3

A process as claimed in claim 1 characterised in that the aromatic sulfonamide and the isocyanate are contacted in the presence of a catalytic amount of a base selected from 1,4-diazabicyclo[2.2.2]octane, potassium carbonate, sodium hydride and potassium tert-butoxide.

Claim 4

A process as claimed in either of claims 1 and 2 characterized in that in the isocyanate of formula (V)X is Cl or Br.

Claim 5

A process as claimed in any one of the preceding claims characterized in that in the isocyanate of formula(V)X is Cl and Y is Cl.

Claim 6

A process as claimed in claim 1. further characterized in that the compound of formula(IV)produced is subsequently subjected to one of the following reaction steps: (a) to prepare a compound of formula (wherein A, X and Z are as defined in claim 1 and R is methyl, ethyl, or -CH 2 C0 2 CH 3 ) the compound of formula (IV) (wherein A, X and Z are as defined in claim 1 and Y is as defined in claim 1) is contacted with at least two equivalents of alkoxide ion, -OR (wherein R is as defined above) and the product obtained thereby is acidified; (b) to prepare a compound of formula (wherein A and Z are as defined in claim 1; R is methyl, ethyl, -CH-CO 2 CH 3 or -CH 2 -CO 2 -CH 3 ; and C H 3 R 1 is methyl or ethyl) the compound of formula (IV) (wherein A and Z are as defined in claim 1: Y is as defined in claim 1; and X is Cl or Br) is sequentially contacted with at least two equivalents of alkoxide ion, -OR (wherein R is as defined above), and subsequently with at least one equivalent of alkoxide ion, -OR 1 (wherein R 1 is as defined above) and the product obtained thereby is acidified; (c) to prepare a compound of formula (wherein A and Z are as defined in claim 1 and R 1 is methyl or ethyl) the compound of formula (IV) (wherein A and Z are as defined in claim 1; Y is as defined. in claim 1; and X is Cl or Br) is contacted with at least three equivalents of alkoxide ion, -OR 1 (wherein R 1 is as defined above) and the product obtained thereby is acidified; and (d) to prepare a compound of formula (wherein A and Z are as defined in claim 1; X" is C 1 -C 2 alkyl, -CF 3 , 2-methoxyethyl, -OCH 3 or methoxymethyl; and E is -NR2R3 or Cl - C6 alkylthio (in which R 2 and R 3 , which may be the same or different, are C 1 -C 4 alkyl)) the compound of formula (IV) (wherein A and Z are as defined in claim 1; Y is as defined in claim 1 ; and X is X" where X" is as defined above) is contacted with (i) at least one equivalent of C 1 -C 6 alkyl mercaptan or at least one equivalent of HNR 2 R 3 (wherein R 2 and R 3 are as defined above), and (ii) at least two equivalents of base, and the product obtained thereby is acidified.

Claim 7

A process as claimed in claim 5 characterized in that in reaction step (a) the compound of formula (IV) is suspended or dissolved in an alkanol solvent of formula ROH (wherein R is as defined in claim 5) in the presence of at least two equivalents of alkoxide ion, -OR (wherein R is defined above).

Claim 8

A process as claimed in either of claims 5 or 6 characterized in that in the said compound of formula (I) X is CïC2 alkyl and R is methyl or ethyl.

Claim 9

. A process as claimed in claim 5 characterized in that in reaction step (b) in the alkoxide ion -OR, R is methyl or ethyl.

Claim 10

A process as claimed in claim 5 characterized in that in reaction step (d) the C 1 -C 6 alkyl mercaptam or secondary amine HNR 2 R 3 , is CH 3 SH, CH 3 CH 2 SH, ( CH 3 ) 2 NH or (CH 3 CH 2 ) 2 NH and in the compound of formula (IV) contacted therewith X is methyl or ethyl.

Claim 11

A process for preparing a compound of formula (wherein A is an optionally substituted homocyclic or heterocyclic aromatic group; X is H; Cl; Br; C 1 -C 2 alkyl; CH 3 0; CH 3 ; methoxymethyl or methoxyethyl; Z is CH, N, C-Cl or C-CH 3 ; and R is methyl, ethyl, or CH 2 CO 2 CH 3 ) characterized in that a compound of formula (wherein Y is Cl or Br and A, X and Z are as defined above) is contacted with at least two equivalents of alkoxide ion, -OR (wherein R is as defined above) and the product obtained thereby is acidified.

Claim 12

A process for preparing a compound of formula (wherein A is an optionally substituted homocyclic or heterocyclic aromatic group; X is H; Cl; Br; C 1 -C 2 alkyl; CH 3 0; CH 3 ; methoxymethyl or methoxyethyl; Z is CH, N, C-Cl or C-CH 3 ; and R is methyl, ethyl, or CH 2 CO 2 CH 3 ) characterized in that a compound of formula (wherein Y is Cl or Br and A, X and Z are as defined above) is contacted with at least two equivalents of alkoxide ion, -OR (wherein R is as defined above) and the product obtained thereby is acidified.

Claim 13

ll. A process for preparing a compound of formula (wherein A is an optionally substituted homocyclic or heterocyclic aromatic group; Z is CH, N, C-Cl or C-CH 3 ; R is methyl, ethyl, or CH 2 CO 2 CH 3 ; and R 1 is methyl or ethyl) characterized in that a compound of formula X (wherein Y is as defined in claim 1; X is Cl or Br; and A and Z are as defined above) is sequentially contacted with at least two equivalents of alkoxide ion -OR 2 (wherein R is as defined above) and subsequently with at least one equivalent of alkoxide ion, -OR 1 (wherein R 1 is. as defined above) and the product obtained thereby is acidified.

Claim 14

A process for preparing a compound of formula i (wherein A is an optionally substituted homocyclic or heterocyclic aromatic group; X" is C 1 -C 2 alkyl, CF 3 , CH 3 0,2-methoxyethyl or methoxymethyl; E is -NR 2 R 3 or C 1 -C 6 alkylthio; R 2 and R 3 are independently C 1 -C 4 alkyl; and Z is CH, N, C-Cl or C-CH 3 ) characterized in that (a) a compound of formula (wherein Y is Cl or Br; X is X" where X" is as defined above; and Z and A are as defined above) is contacted with (i) at least one equivalent of CI-C6 alkyl mercaptan or at least one equivalent of HNR 2 R 3 and (ii) at least two equivalents of base; and (b) the product of step (a) is acidified.

Claim 15

A process for preparing a compound of formula i (wherein A is an optionally substituted homocyclic or heterocyclic aromatic group; X" is C 1 -C 2 alkyl, CF 3 , CH 3 0,2-methoxyethyl or methoxymethyl; E is -NR 2 R 3 or C 1 -C 6 alkylthio; R 2 and R 3 are independently C 1 -C 4 alkyl; and Z is CH, N, C-Cl or C-CH 3 ) characterized in that (a) a compound of formula (wherein Y is Cl or Br; X is X" where X" is as defined above; and Z and A are as defined above) is contacted with (i) at least one equivalent of CI-C6 alkyl mercaptan or at least one equivalent of HNR 2 R 3 and (ii) at least two equivalents of base; and (b) the product of step (a) is acidified.

Claim 16

A process as claimed in any of the preceding claims characterized in that substituent A is a group selected from optionally substituted phenyl, napthyl, furanyl, thienyl and pyridyl groups.

Claim 17

A process as claimed in any of the preceding claims characterized in that substituent A is a group selected from ortho-substituted phenyl, 2-furanyl, 2-thienyl, 3-thienyl, 2-substituted-3-thienyl, 4-substituted-3-thienyl, ortho-substituted pyridyl, ortho-carboxylic acid or carboxylic acid amide substituted phenyl and ortho pyrrolidine carboxamide substituted phenyl groups.

Claim 18

A process as claimed in any of the preceding claims characterized in that Z in compounds containing group Z is CH or N.