| 摘要 |
Substd. pyridine derivs. of formula (I) are new: R1 = OH or Cl; (a) X = H or Cl; and R2+R3 = oxo; R4 = OR5; R5 = H, 1-4C alkyl or benzyl; (b) X = H and R2, R3 and R4 are together =NH-NH-; (c) X=R2=H, and R3 and R4 are together -O-; (d) X=R2=H;R3 = OH and R4 = OH or NH2; the cpd. with X=H; R1 = R4 = OH and R2+R3 = OXO is excluded. (I) may be prepd. by e.g. first oxidising nicotine with Pseudomonas or Variovorax, to give 5-succinoyl-2-pyridone and converting this to ester (II; R'5 = 1-4C alkyl or benzyl). The 2-OH is opt. replaced by Cl (esp. reaction with POCl3) and the product cyclised with hydrazine to give cpds. of (b) above. Specified microorganisms are P. putida DSM 8231 or 8236; P. fluorescens DSM 8235; P. sp. DSM 8653 or V. paradoxus DSM 8244. These can tolerate a high nicotine concn. (pref. 5-20 g/l) and provide high yields and concn. of product. |
