Patent ID: 7893284

Claim:
A compound of the formula wherein R 1 is group selected from any one of —OH, or a sulphamate group of the formula wherein R 5 and R 6 are independently selected from H, alkyl, cycloalkyl, alkenyl and aryl, or combinations thereof, or together represent alkylene, wherein the or each alkyl or cycloalkyl or alkenyl or aryl optionally contains one or more hetero atoms or groups; R 2 is a group of the formula -L-R 3 , wherein L is an optional C 1-10 alkylene group and R 3 is a nitrile group, or R 3 is: (a) a group of the formula —(R 7 ) n (CR 14 R 15 ) p R 8 wherein n is 0 or 1, p is from 0 to 5; R 7 is selected from ═CH—, —O— and NR 13 ; R 8 is —C≡N; R 13 is selected from H and C 1-10 alkyl; R 14 and R 15 are each independently selected from H and C 1-10 alkyl; or (b) a group of the formula —(CR 14 R 15 ) p R 8 , wherein p is from 0 to 5, R 8 is —C≡N, R 14 and R 15 are each independently selected from H and C 1-10 alkyl; or (c) a group of the formula —(CH2) p R 8 , wherein p is from 0 to 5, R 8 is —C≡N; or (d) a group of the formula —(R 7 ) n R 8 wherein n is 0 or 1, R 7 is selected from ═CH—, —O— and NR 13 , R 8 is —C≡N, and R 13 is selected from H and C 1-10 alkyl; wherein R 4 is an alkyl or alkoxy group.