(6f) 5-(4-methoxy phenyl)-4-methyl-3yl- (Imidazolidin-1ylmethyl, 2-ylidene nitro imine)isoxazole IR: νmax 3354, 1553, 1412 cm−1, 1H NMR: δ 3.9 (s, 3H, –OCH3), 5.5 (s, 2H, –CH2–N–), 2.4 (s, 3H, isoxazole–CH3),2.0 (brs, 1H, –NH), 2.65–3.1 (m, 4H), 7.0 (d, 2H, Ar.H), 7.3–7.4 (m, 2H, Ar.H), EI mass (m/z) 331 (M+), 262, 180. (6g) 5-(2-chlorophenyl)-4-methyl-3yl-(Imidazolidin-1ylmethyl, 2-ylidene nitro imine) isoxazole IR: νmax: 3318, 1587, 1410, 1310 cm−1, 1H NMR: δ 5.5 (s, 2H, –CH2N–), 2.4 (s, 3H, isoxazole–CH3), 2.2 (brs,1H,–NH), BGB324 concentration 2.7–3.0 (m,

4H),6.9 (m, 1H, Ar.H) 7.3–7.6 (m, 3H, Ar.H),7.9(m, J = 8.25, 1H, Ar.H), EI (m/z) 335(M+),263,135. (6h) 5-(2-methoxyphenyl)-4-methyl-3yl-(Imidazolidin-1ylmethyl, 2-ylidene nitro imine) isoxazole IR: νmax: 3350,

1550, 1415, 1298 cm−1, 1H NMR: δ 3.9 (s, 3H, –OCH3), 4.6 (s,2H, –CH2N–), 2.3(s, 3H, isoxazole–CH3),2.1 (brs, 1H, –NH), 2.6–3.0 (m, 4H), 7.0 (d, J = 8.3Hz, 2H, Ar.H), 7.1 (t,J = 7.6Hz, 1H, Ar.H), 7.4(t, J = 7.4 Hz, 1H, Ar.H),7.8 (d, J = 7.6 Hz, 1H, Ar.H), EI mass (m/z) 331 (M+),265, 170. (6i) 5-(3-methoxyphenyl)-4-methyl-3yl-(Imidazolidin-1ylmethyl,2-ylidenenitroImine) isoxazole. IR: νmax: 3330, 1567, 1410 cm−1, 1H NMR: δ 3.8 (s, 3H, OCH3), 5.5 (s, 2H, –CH2–N), 2.35 (s, –CH3, isoxazole), 2.2 (brs, 1H, –NH), 2.7–3.1 (m, 4H), 6.9 (m, 1H, Ar.H), 7.2–7.4 (m, 3H, ArH), EI mass (m/z) 331 (M+), 264, 175. (6j) 5-(3-chlorophenyl)-4-methyl-3yl-(Imidazolidin-1-ylmethyl, 2-ylidene nitro imine)

isoxazole IR: νmax: 3304, Smad inhibitor GBA3 1589, 1428, 1312 cm−1, 1H NMR : δ5.6(s, 2H, –CH2–N), 2.35(s, –CH3, isoxazole), 2.1 (brs, 1H, –NH), 2.64 (t, 2H, N–CH2), 2.8–3.1 (m, 4H), 7.4 (m, 2H, ArH) 7.7 (m, 1H, ArH),7.8 (m, 1H, ArH), EI mass (m/z) 335 (M+), 260, 171. (6k) 5-(2,4 di methoxyphenyl)-4-methyl-3yl-(Imidazolidin-1ylmethyl, 2-ylidene nitro imine) isoxazole IR: νmax: 3331, 1555, 1418 cm−1, NMR: δ 3.8 (s, 3H, OCH3), 3.9 (s, 3H, OCH3), 5.4 (s, 2H, –CH2–N), 2.38 (s, CH3, isoxazole), 2.1 (brs, NH), 2.8–3.0 (m, 4H), 6.45 (d, 1H, ArH, J = 3.0 Hz), 6.55 (dd, 1H, Ar.H, J = 8.4 and 3.0), 7.8 (d, 1H, ArH), EI mass (m/z) 361 (M+), 267, 105, 77. In the present study we found that the exclusive formation of one isomer methyl-5-(phenyl/substituted phenyl)-3-isoxazole-carboxylate. A rigorous study on the direction of enolisation of disubstituted β-ketones was reported.15 When the substituents are not the electronically very different the separation of the 3,5 disubstituted isomers is difficult.