Context : The present number of Galactic Open Clusters that have high resolution abundance determinations , not only of [ Fe/H ] , but also of other key elements , is largely insufficient to enable a clear modeling of the Galactic Disk chemical evolution .

Aims : To increase the number of Galactic Open Clusters with high quality measurements .

Methods : We obtained high resolution ( R \sim 30 000 ) , high quality ( S/N \sim 50-100 per pixel ) , echelle spectra with the fiber spectrograph FOCES , at Calar Alto , Spain , for three red clump stars in each of five Open Clusters .
We used the classical Equivalent Width analysis method to obtain accurate abundances of sixteen elements : Al , Ba , Ca , Co , Cr , Fe , La , Mg , Na , Nd , Ni , Sc , Si , Ti , V , Y .
We also derived the oxygen abundance through spectral synthesis of the 6300Â Ã Â forbidden line .

Results : Three of the clusters were never studied previously with high resolution spectroscopy : we found [ Fe/H ] =+0.03 \pm 0.02 ( \pm 0.10 )  dex for Cr 110 ; [ Fe/H ] =+0.01 \pm 0.05 ( \pm 0.10 )  dex for NGC 2099 ( M 37 ) and [ Fe/H ] =–0.05 \pm 0.03 ( \pm 0.10 )  dex for NGC 2420 .
This last finding is higher than typical recent literature estimates by 0.2–0.3Â dex approximately and in better agreement with Galactic trends .
For the remaining clusters , we find : [ Fe/H ] =+0.05 \pm 0.02 ( \pm 0.10 ) Â dex for MÂ 67 and [ Fe/H ] =+0.04 \pm 0.07 ( \pm 0.10 ) Â dex for NGCÂ 7789 .
Accurate ( to \sim 0.5 km s ^ { -1 } ) radial velocities were measured for all targets , and we provide the first high resolution based velocity estimate for Cr 110 , < V _ { r } > =41.0 \pm 3.8 km s ^ { -1 } .

Conclusions : With our analysis of the new clusters Cr 110 , NGC 2099 and NGC 2420 , we increase the sample of clusters with high resolution based abundances by 5 % .
All our programme stars show abundance patterns which are typical of open clusters , very close to solar with few exceptions .
This is true for all the iron-peak and s-process elements considered , and no significant \alpha -enhancement is found .
Also , no significant sign of ( anti- ) correlations for Na , Al , Mg and O abundances is found .
If anticorrelations are present , the involved spreads must be < 0.2Â dex .
We then compile high resolution data of 57 OC from the literature and we find a gradient of [ Fe/H ] with Galactocentric Radius of –0.06 \pm 0.02 dex kpc ^ { -1 } , in agreement with past work and with Cepheids and B stars in the same range .
A change of slope is seen outside R _ { GC } =12Â kpc and [ \alpha /Fe ] shows a tendency of increasing with R _ { GC } .
We also confirm the absence of a significant Age-Metallicity relation , finding slopes of –2.6 \pm 1.1 10 ^ { -11 }  dex Gyr ^ { -1 } and 1.1 \pm 5.0 10 ^ { -11 }  dex Gyr ^ { -1 } for [ Fe/H ] and [ \alpha /Fe ] respectively .