3-Methoxy 4-alkoxy benzaldehyde(s) - useful as intermediates for antibacterials, esp. trimethoprim and tetroxoprim

摘要

Benzaldehyde derivs. of formula (I) are new (where R1 = CHO, in which case R2 = halogen and R3 = CH3OCH2CH2-, or R1 = -CH(AR) (BR') A and B = O or S; R and R' = lower alkyl or, together with CHAB form a cyclid gp., in which case R2 = halogen or CH30, and R3 = CH3OCH2CH2 or 1-4 C alkyl). Used as intermediates for the prepn. of antibacterial agents, such as trimethoprim and tetroxoprim. The process for preparing the antibacterial agents is easier to carry out than known methods, and gives better yields.