Patent ID: 7807838

Claim:
A compound of formula (IV), wherein: R 4 is selected from hydrogen, C 1 -C 6 alkyl, —(CR 9 R 10 ) n R 11 , —CF 3 , halogen, —OR 12a , —CN, and —NR 12a R 12b ; R 5 is selected from hydrogen, C 1 -C 6 alkyl, —(CR 9 R 10 ) n R 11 , —CF 3 , halogen, —OR 12a , —CN, and —NR 12a R 12b ; R 6 is selected from hydrogen, C 1 -C 6 alkyl, —(CR 9 R 10 ) n R 11 , —CF 3 , halogen, —OR 12a , —CN, and —NR 12a R 12b ; R 7 is selected from hydrogen, C 1 -C 6 alkyl, —(CR 9 R 10 ) n R 11 , —CF 3 , halogen, —OR 12a , —CN, and —NR 12a R 12b ; each R 9 and R 10 is independently selected from hydrogen and C 1 -C 6 alkyl, or R 9 and R 10 , together with the carbon atom to which they are attached, form a C 3 -C 6 cycloalkyl group; each R 11 is independently selected from hydrogen, C 1 -C 6 alkyl, halogen, —OR 12a , —CN, —CF 3 , and —NR 12a R 12b ; each R 12a and R 12b is independently selected from hydrogen and C 1 -C 6 alkyl; R 13 is hydrogen, C 1 -C 6 alkyl, —Si(C 1 -C 6 alkyl) 3 , or —CH 2 (C 6 -C 10 aryl), wherein said C 6 -C 10 aryl group is optionally substituted with at least one substituent selected from halogen, C 1 -C 6 alkyl, —OH, —OCH 3 , and —N(C 1 -C 6 alkyl) 2 P 1 is hydrogen or a suitable protecting group; and each n is independently chosen and is an integer from 0 to 5.